Persisting refusal to close my Discovery credit card

On the 23rd of October I sent a notification to close my Discovery credit card. I paid all the outstanding fees and had a positive balance just under R30. However, my account was still open at the end of November and fees were charged. I sent another an e-mail on the 27th of November enquiring about the status of my account, I was then sent a closure form. I sent through the signed closure form but my account was still open and I was told to fill in my account number for a refund. I rep**** on the 12th of December stating that I don't want that amount they can put it in their suspense account, I just want my account to be closed. Thereafter, I sent several communications without any response.