FNB REQUESTING INFO THEY NEVER EVEN GAVEV ME!!

I have logged a purchase reversal, and on the form i have clearly stated i do not have the account number for my credit card because it WAS NEVER GIVEN TO ME!! When i opened the credit card, it was not even stated on the letter that came with the card, each time i asked for the account number im never assisted, and now FNB is wanting to hold back my reversal request because of something that was never made known to me!!!