AFRICAN BANK WANTS MORE MONEY

I have to say that i'm really not happy with African Bank, reason being i went into the branch for settlement figures - which they did provide me with and i have letters to prove that. The settlement given was paid the very next day, only for me to now receive a message from them stating that i now owe a further R7000.00 and further more they still debit my account, now i would call this *****. I beleive that the whole idea of asking for a settlement amount is just that a final payment and not for them to now come up with an outstanding amount still owing, or what would be the idea of asking for a settlement amount. They will not be getting any more money from me nor would i be dealing with them in the future. They will just have to rectify the mistake.