Discovery Bank - Please close my paid up cc and provide written confirmation

I have been trying to close my Discovery Bank CC for the past week; I refer to the reference number ***7 for the call on 02 Oct at 08:40 which was not the first time I requested it but the latest request where i specifically asked for a paid up letter confirming this credit card is paid up and closed, yet here I am still waiting and waiting and waiting .

Its not difficult Discovery Bank, please CLOSE THIS ACCOUNT AND SHARE THE WRITTEN CONFIRMATION THERE OF.