Nedbank Credit card rogues

We are being charged for a paid up credit card debt and haven't received a new card in over 10 years yet we are charged a monthly fee for something we don't have. Plain *****ing money from old people I would say. I tried contacting them from my work and was told they have to speak to my husband in order to cancel the "card". We have sent an letter signed by my husband via email years ago that I will take over paying off the debt. That was finished years ago. Now we're being harassed for something we don't even have. Irene van Wyk