Wont cancel my Credit Card account

About 2 weeks ago, I contacted Discovery to cancel my credit card and was told by the agent that they wouldn't do it then but that they would send me the balance to settle and have someone contact me within 48 hours to confirm the cancellation.

I have yet to be contacted. Since settling the balance, I see that Discovery has charged me about R50 on my card.

All I want to do is cancel my card. Why is it so hard?