Extra charges even after settling the account

14 December I asked for settlement for my credit card and I paid through their so called immediate payment system where they use my card details as if I am paying for something online. It took forever for the money of immediate payment to reflect, even 3 working days later it had still not reflected until I made noise. On the 3rd working day late in the evening after making noise I asked them to close the account as I had settled it. They initiated closure of which I got an sms for and told me it take 3 working days to close. I am on the 4th working day and it's still not closed, when I call to ask what's going on they are telling me I need to pay a further R1800 for deposit fee. I am fuming as it is because I did the same with my amex credit card and within 3 working days the account was closed without extra charges. Yet the nedbank money I owed was more than the african bank money and now over 7 working days later. The account needs me to pay extra money which nobody warned me of. It's bad enough their interest rates are so high, worse if after settling I have to pay a whole R1800 extra, I ask myself what settlement means