Cannot close credit card account

I've been trying for several months now to close my Discovery Bank credit card account, but it has proved to be a terribly frustrating experience. Firstly, Discovery Bank has a special help line for closures but, for some reason, is hardly ever answered. With the changeover to Discovery Bank, one gets a new account number. I had to try several times to find out how I could settle my account by EFT, before I got a positive answer. Just getting a settlement figure took several weeks. Eventually, I managed to settle my account but, despite several attempts, cannot get through to them on the relevant helpline to request a closure. The bank's service leaves a lot to be desired.