Failure to cancel credit card account

Since late September 2015 I have been trying to cancel a credit card account. I have phoned numerous times and Nedbank keeps failing to close the account as I request telephonically with them. I recently (2 weeks ago) called them to let them know that the account had still not been closed and that there was a new admin fee deducted by them on the account. They apologised and said they would close the account and remove the admin fee. I checked my online banking again and the admin fee has been removed but the account is still open! This is very disappointing. I have phoned numerous times from overseas now and this is becoming a real and costly hassle. I do not want to have to phone again to resolve something that should have been done properly in September.