No service when closing your credit card

I settled my credit card and made an additional payment of R33.00 as requested but credit card still active. Phone in to request the card to be cancelled following day as it is only customer care department that cancel the card and supply me with a letter to state the account has been closed.

I spent 20minutes yesterday on the phone, today another 20minutes no card cancellation done and no letter.

Please cancel my credit card and supply me with a closure account letter to update my credit report all I'm asking.