EX Wife forged Signature
An affidavit might work.
I bet paperwork from the DA prosecuting your ex would serve to nicely crystalize things in the mind of the bank in question.
If the DA believes "Bob didn't apply for this credit" and is willing to send someone to jail over it, the bank is likely going to listen when Bob says "Take it off my report or I'm suing for libel."
In fact, depending on how negligent the bank has been in reporting, and how much documentation you have already provided the bank, they may already have opened themselves up to a substantial civil judgement.
654 Equifax FICO October 2004