here is the code and highlighted is the line where it is breaking.

(sent in two parts because of the lenth)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
using System.Net;
using System.Threading;
using BulkApi.com.salesforce.na15;
using System.Diagnostics;
using System.Xml;
using System.Xml.XmlConfiguration;
using System.Web.Services.Protocols;
using BulkApi.Properties;
using System.Web;
using System.Security.Policy;


namespace BulkApi
{
    class Program
    {
        private  void QueryUsingBulkAPI()
       {
           string jobId = string.Empty;
            string resultId = string.Empty;
            string batchId = string.Empty;
            Console.Write("Enter user name: ");
            string userName = Console.ReadLine();
            Console.Write("Enter password: ");
            string password = Console.ReadLine();
  Console.WriteLine("Creating the binding to the web service...")
 SforceService service = new SforceService();
             service.Timeout = 60000;

             Console.WriteLine("LOGGING IN NOW....")
 try
            {
                LoginResult loginRes = service.login(userName, password);
                Console.WriteLine(loginRes);
                Console.WriteLine("The session id is: " + loginRes.sessionId);
                Console.WriteLine("The new server url is: " + loginRes.serverUrl);
              
             
                service.Url = loginRes.serverUrl;

             
                service.SessionHeaderValue = new SessionHeader();
                service.SessionHeaderValue.sessionId = loginRes.sessionId;
                Debug.WriteLine(loginRes.sessionId);

                CreateJob(loginRes.sessionId,"query","case",jobId);
              
              
                byte[] inputFileData = null;

                if ((jobId.Length > 0))
                {
                  
                    System.IO.FileInfo oFile = null;
              
                    oFile = new System.IO.FileInfo("request.txt");

                    System.IO.FileStream oFileStream = oFile.OpenRead();
                    long lBytes = oFileStream.Length;
                    int a = (int)lBytes;
                    if ((lBytes > 0))
                    {
                        byte[] fileData = new byte[lBytes];
                       
                        oFileStream.Read(fileData, 0, a); 
                        oFileStream.Close();

                       
                        inputFileData = fileData;
                    }

                 
                    AddBatch(loginRes.sessionId, inputFileData, jobId, batchId, resultId);

                   GetStatusAndRetrieveBatchIdAndResultsId(loginRes.sessionId, jobId,  batchId,  resultId);
                   
                   RetrieveResults(loginRes.sessionId, jobId, batchId, resultId);
                }
            }
            catch (System.Web.Services.Protocols.SoapException e)
            {
               
                Console.Write(e.Message + ", please try again." + "Hit return to continue...");
                Console.ReadLine();

            }
            catch (Exception ex)
            {
               
                Console.Write(ex.Message + ", please try again." + "Hit return to continue...");
                Console.ReadLine();

            }
}
               public void CreateJob(string sfSessionId, string sfOperation, string sfObjectName, string jobId)
               {
                  string str = string.Empty;
                  string reqURL  = string.Empty;
                  byte[] bytes = null;
      
                  XmlDocument reqDoc = default(XmlDocument);
                  XmlDocument responseXmlDocument = new XmlDocument();
             
                   str = ""+"<?xml version=\"1.0\" encoding=\"UTF-8\"?>" + "<jobInfo xmlns=\"http://www.force.com/2009/06/asyncapi/dataload\">"
                           + "<operation></operation>" + "    <object></object>" + "<contentType>XML</contentType>" + "</jobInfo>";

                   reqURL = "https://na15-api.salesforce.com/services/async/29.0/job/";
                   reqDoc = new XmlDocument();
                   reqDoc.LoadXml(str);
     
          
                    // added XML modifications


                    reqDoc.GetElementsByTagName("operation")[0].InnerText = sfOperation;
                    reqDoc.GetElementsByTagName ("object")[0].InnerText =  sfObjectName;
                    bytes = System.Text.Encoding.ASCII.GetBytes(reqDoc.InnerXml);
                    using (Stream responseStream = Post(bytes, reqURL, sfSessionId, "POST", "text/csv;charset=UTF-8"))
                    {
                        responseXmlDocument.Load(responseStream);
                        //Get jobId
                        jobId = ((((responseXmlDocument) != null)) ? responseXmlDocument.GetElementsByTagName("id").Item(0).InnerText : "");
                    }
                } 
                   public void AddBatch(String sfSessionId,
                            Byte[] fileBytes,
                            String sfJobId,
                            string sfBatchId,
                            string resultid)//check how to define optional parameter in C# i think it doesnt allow?
                      {

                          String requestURI = ("https://login.salesforce.com/services/async/29.0/job/" +
                           (sfJobId + "/batch"));
                          Post(fileBytes, requestURI, sfSessionId, "POST", "text/csv;charset=UTF-8");

                       }


                    public void GetStatusAndRetrieveBatchIdAndResultsId(string sfSessionId, string sfJobId,  string batchId,  string resultId)
     
                          {
                             XmlDocument responseXmlDocument = new XmlDocument();
                             String reqURL = ("https://na15-api.salesforce.com/services/async/29.0/job/" +
                             sfJobId + "/batch");
                             using (Stream responseStream = Post(null, reqURL, sfSessionId, "GET", "text/csv;charset=UTF-8"))
                                {
                                   responseXmlDocument.Load(responseStream);
                                   batchId = ((((responseStream) != null)) ? responseXmlDocument.GetElementsByTagName("id").Item(0).InnerText : "");
                                 }

                             
                             reqURL = ("https://na15-api.salesforce.com/services/async/29.0/job/" +
                                (sfJobId + "/batch/" + batchId + "/result"));

                             using (Stream responseStream = Post(null, reqURL, sfSessionId, "GET", "text/csv;charset=UTF-8"))
                                {
                                   responseXmlDocument.Load(responseStream);
                                   resultId = ((((responseStream) != null)) ? responseXmlDocument.GetElementsByTagName("result").Item(0).InnerText : "");
                                }
     
                          }