URGENT : I am getting an error in apex class i am trying to insert oppurtunity and line items .

ERROR : System.DmlException: Insert failed. First exception on row 0; first error: FIELD_INTEGRITY_EXCEPTION, field integrity exception: PricebookEntryId (pricebook entry currency code does not match opportunity currency code): [PricebookEntryId]: 

Apex Class : public class UpdateOpptyLineItems{
    public static void UpdateLineItems(List<OpportunityLineItem> oliList,Double ExportQuantity,string Operation){
        List<OpportunityLineItem> oliListToBeUpdated = new List<OpportunityLineItem>();        
        Date PreviousDate = System.Today();
        Date CurrentDate = System.Today();
        Map<Date,List<OpportunityLineItem>> dateFinalOli = new Map<Date,List<OpportunityLineItem>>();
        for(OpportunityLineItem oli:oliList){
            if(dateFinalOli.containsKey(Date.ValueOf(oli.ServiceDate))){
                dateFinalOli.get(Date.ValueOf(oli.ServiceDate)).add(oli);
            }
            else{
                List<OpportunityLineItem> oliList1 = new List<OpportunityLineItem>();
                oliList1.add(oli);
                dateFinalOli.put(Date.ValueOf(oli.ServiceDate),oliList1);
            }
        }
        system.debug('dateFinalOli : ' + dateFinalOli);        
        for(Date dt:dateFinalOli.KeySet()){
            Integer i=0;
            for(OpportunityLineItem oli:dateFinalOli.get(dt)){                
                if(oli.Tipo__c == '1.Estoque Inicial'){                     
                    if(i != 0){
                        if(Operation == 'Remove'){
                            oliListToBeUpdated.add(new OpportunityLineItem(Id = oli.Id,Quantity = oli.Quantity - ExportQuantity, TotalPrice = oli.TotalPrice));       
                        }
                        if(Operation == 'Add'){
                            oliListToBeUpdated.add(new OpportunityLineItem(Id = oli.Id,Quantity = oli.Quantity + ExportQuantity, TotalPrice = oli.TotalPrice));       
                        }
                    }
                }                        
                if(oli.Tipo__c == '6.Estoque Final'){    
                    if(Operation == 'Remove'){
                        oliListToBeUpdated.add(new OpportunityLineItem(Id = oli.Id,Quantity = oli.Quantity - ExportQuantity,TotalPrice = oli.TotalPrice ));
                    }
                    if(Operation == 'Add'){
                        oliListToBeUpdated.add(new OpportunityLineItem(Id = oli.Id,Quantity = oli.Quantity + ExportQuantity,TotalPrice = oli.TotalPrice));
                    }
                }       
                i++;    
            }
        }
        system.debug('Final OLI List : ' + oliListToBeUpdated);
        if(!oliListToBeUpdated.isEmpty()){
            update oliListToBeUpdated;
        }
    }
    public static void UpsertLineItems(List<Opportunity> oppImportFinalRec,Integer StartingMonth,Id pbID,Double ImportQuantity, Decimal UnitPrice){
        List<OpportunityLineItem> oliList = new List<OpportunityLineItem>();
        List<OpportunityLineItem> oliListInsert = new List<OpportunityLineItem>();
        Map<Date,List<OpportunityLineItem>> dateFinalOli = new Map<Date,List<OpportunityLineItem>>();
        for(OpportunityLineItem oli:oppImportFinalRec[0].OpportunityLineItems){
            if(dateFinalOli.containsKey(Date.ValueOf(oli.ServiceDate))){
                dateFinalOli.get(Date.ValueOf(oli.ServiceDate)).add(oli);
            }
            else{
                List<OpportunityLineItem> oliList1 = new List<OpportunityLineItem>();
                oliList1.add(oli);
                dateFinalOli.put(Date.ValueOf(oli.ServiceDate),oliList1);
            }
        }       
        system.debug('dateFinalOli : ' + dateFinalOli); 
        for(Integer I=StartingMonth;i<=12;i++){
            Date ServiceDate = Date.newInstance(oppImportFinalRec[0].CloseDate.Year(), I, 1);
            System.debug('ServiceDate : ' + ServiceDate);
            if(dateFinalOli.containsKey(ServiceDate)){
                for(OpportunityLineItem oli:dateFinalOli.get(ServiceDate)){
                    if(oli.Tipo__c == '1.Estoque Inicial'){
                        if(I!= StartingMonth){
                            oliList.add(new OpportunityLineItem(Id = oli.Id,Quantity = oli.Quantity + ImportQuantity));
                        }
                    }
                    if(oli.Tipo__c == '6.Estoque Final'){
                        oliList.add(new OpportunityLineItem(Id = oli.Id,Quantity = oli.Quantity + ImportQuantity));
                    }
                }
            }
            else{           
                if(I!= StartingMonth){
                    oliListInsert.add(new OpportunityLineItem(ServiceDate = ServiceDate,PriceBookEntryId = pbID,OpportunityId = oppImportFinalRec[0].Id,Tipo__c = '1.Estoque Inicial',Quantity = ImportQuantity,UnitPrice = UnitPrice));
                }           
                oliListInsert.add(new OpportunityLineItem(ServiceDate = ServiceDate,PriceBookEntryId = pbID,OpportunityId = oppImportFinalRec[0].Id,Tipo__c = '6.Estoque Final',Quantity = ImportQuantity,UnitPrice = UnitPrice));
            }
        }
        system.debug(' Update List : ' + oliList);
        system.debug(' Insert List : ' + oliListInsert);
        if(!oliList.isEmpty()){
            update oliList;
        }
        if(!oliListInsert.isEmpty()){
            insert oliListInsert;
        }
    }
    public static void InsertLineItems(Integer StartingMonth,string OppID, Id pbID,Double ImportQuantity, Decimal UnitPrice){
        List<OpportunityLineItem> oliList = new List<OpportunityLineItem>();
        for(Integer I=StartingMonth;i<=12;i++){
            if(I!= StartingMonth){
                oliList.add(new OpportunityLineItem(PriceBookEntryId = pbID,OpportunityId = OppID,Tipo__c = '1.Estoque Inicial',Quantity = ImportQuantity,UnitPrice = UnitPrice));
            }
            oliList.add(new OpportunityLineItem(PriceBookEntryId = pbID,OpportunityId = OppID,Tipo__c = '6.Estoque Final',Quantity = ImportQuantity,UnitPrice = UnitPrice));
        }
        if(!oliList.isEmpty()){
           insert oliList;
       }       
    }
    public static Id InsertOpportunity(Id pbID,string AccountName,string AccountID,string RegionID,string RegionName,string MainYear,string ImportRegionOwner){
        ID recTypeOppPadrao = RecordTypeMemory.getRecType( 'Opportunity', 'Padrao' );
        Periodo_da_Oportunidade__c po = Periodo_da_Oportunidade__c.getInstance();
        system.debug(po.Periodo_Aberto_Ate__c);
        Database.saveresult insOpp;
        String oppName = '';
        oppName += AccountName;
        oppName += ' - '+ MainYear;
        oppName += ' - ' + RegionName;
        Opportunity opp = new Opportunity();
        opp.RecordTypeId = recTypeOppPadrao;
        opp.Name = oppName;
        opp.Owner = new User (Id = ImportRegionOwner);
        opp.AccountID = AccountID;
        opp.CloseDate = Date.ValueOf(po.Periodo_Aberto_Ate__c); 
        opp.Pricebook2Id  = pbID;
        //opp.CloseDate = System.today() + 90;   
        opp.StageName = 'RFC';
        opp.Micro_Regiao_Principal__c = RegionID;       
        insOpp = (Test.isRunningTest()) ? null : Database.insert(opp);
        return insOpp.getId();
    }   
}