Deliberately difficult processes to try dissuade cancellations

Phoned the call centre to cancel my credit card. I'm told I owe R22 despite my Money App showing a zero balance. Transferred the money, and then I'm told I have to wait for it to clear, despite it being Nedbank to Nedbank. Phone back a few days later only to be told I now owe R32 - my Money App says zero balance - because they've charged me fees despite my cancellation request and payment - surely this is *********? I transfer the money anyway and I'm told to call back in a few day's time again. Absolutely ridiculous. I've given the instruction to cancel the card, and they have proof of the transfer. Why am I having to phone yet again? They have proof of my request to cancel - why do they need me to phone yet again!?