FNB: really disappointing !

Really disappointed in FNB! For 3 weeks now I have been going in to my local branch in order to make a payment to my credit card. We have tried everything possible, internet banking, cellphone banking, transfer at the ATM and cash deposit. But I keep getting the same message that the transaction cannot be completed. The lady at the local branch has been very helpful and should get a meddle for dealing with me every week but unfortunately she can only do so much to assist me. She’s been on the phone countless times with the collections department, but It is as if the collections department does not want to assist. I really don’t know what to do anymore to make payment To my credit card, and I’m really getting annoyed with FNB.