Bummer. Only other thing I can think of is if you received some sort of confirmation of the transfer.

As for the collections, you can ask them to validate the debt. They must give proof that your debt is valid and belongs to you. The proof may give insight on the state of the utility account, like if its just your name and SSN or if it also includes your roommate. If the collection’s can’t provide valid proof, then they can’t legally collect. You can tell them to kick rocks. From there, you can contact the credit agencies to remove the invalid collection mark on the report.