Help :(

I've followed this guide for setting up Office 365 as a Connected App:
 
but I'm just getting an error when I click the app:
 
not too bad, as I was just testing but now no one can login to Office 365 as it is redirecting to my Dev Org...

I've tried this command:
 
from here:
 
but its still doing the same. How do I turn this off, I'm guessing I've got to change the IssuerUri, but to what?