Ridiculous service for credit card cancellation

I have a credit card I have been sing for a few months and everything was fine, today I decide to pay it up. I paid it up and settled the account the called in to get it cancelled, I am now being told I owe R59 that I have to pay before the cancel it fully, the amount is not even reflecting on my side. I ask to speak to the manager and then told to hold, when the call goes through to the manager then hangs up.

What are we being taken for? You can't just add interest out of the blue because I am settling my account.