Debited twice for credit card payment

FNB debited me twice for a credit card payment on 25 July & 1 Aug. I called to request them to fix the issue and they said they would reverse the 1 Aug payment. Now I can’t access my account because apparently I didn’t make the minimum payment which i did on 25 July. This is ****************! I spoke to Bonginkosi Buthelezi from FNB who says he cannot help me. Can you please fix this mess because I paid my account but I’ve been handed over to collections for a mistake the bank did!