FNB refuse to close my transactional account

I have an FNB Account that I need to close, since I'm not using it anymore. I've put myself under debt review, and FNB created one account for everything that I was owing them, which it's getting paid monthly. So now I want to close my day to day account, which has a positive balance, but FNB is refusing to close it, while they charge my their monthly fee and take those fees and add them to that one account that is being paid every month. They telling me that I have to first pay the other account in full before they can close my day to day account, If feel that it's not fair because they make me to pay their monthly fees every month. I think they are professional mafia's.