Nedbank making me pay because THEY DID NOT DO THEIR JOB!

I paid off my credit card debts IN FULL and immediately contacted Nedbank to close off the credit account. This was on 27 October. In the beginning of November, bank charges went off on the credit after it was suppose to be closed. I went into a branch to try rectify the issue and was told that the branch can't do anything, I have to call the Nedbank Card department (how a branch can't assist on such matters makes no logical sense by the way). So after speaking with the card department, they advised the issue would be escalated and the amount that went off will not have to be paid by us. Now later this month I made a payment, and my app chose the credit card by default, AFTER IT WAS SUPPOSE TO BE CLOSED....AGAIN!. Now after raising this issue a third time, I was advised the reason the credit account was not closed off was because information was missing. I provided that information and was told that the account can be closed once I pay the outstanding amount. That is absolute BS! If information was missing in the request to close the account, why was this information not requested for? Why did your consultants NOT ask for this information during our discussions?? Now because you guys drop the ball and didn't do YOUR job properly THREE (3) TIMES, I must still fit the bill?? NO! I will NOT be paying that amount and demand that Nedbank take responsibility for this. Paying off that credit debt was almost my entire bonus!