Changing bank account on managed payments

[abundant-deals]

So I made the one mistake you can't do, and wrote a wrong bank account number in my payments settings. Payments have been sent and returned to eBay because the bank account is wrong. When I try to change the bank account to the correct one it asks me to provide the bank account number that I have used (I don't remember the mistake I made and therefore cannot provide it). I tried contacting eBay payments for several days and no one is helping me.

Anyone knows what to do?