Please close my Nedbank Credit Card

I have been trying to close my Nedbank Credit Card for almost a year now. I have reference numbers, etc, but they are refusing to close my account, even though it is paid up. Apparently I am too good a customer for them to close my account. I am so sick of Nedbank, just close my credit card. I am refusing to do further business with you and if need be, I will take this further. You cannot refuse to close MY account.