FNB system causes problems on customers credit profile

I have a account with FNB that I tried to pay but couldn't.

I also went into the branch to get some help on how to pay the account whereby the lady told me that they cannot access that account..

I spent a couple of hours on that day in the branch to see how we can sort it out but I still don't have a answer.

The fact that that money (R234) is outstanding causes problems on my credit score.

Please guys. Sort your stuff out.