Nedbank Amex holding me hostage

I have been trying to close my credit card account for 9 days and counting. I have 2 references and a branch visit to accompany me but not one seems to be able to close it. The branch told me they cannot help at all, the call centre also just gives references and promises that someone will call me back. The last call centre agent told me that no one would call me, he doesn't know why I was told that, and gave me yet another reference and a claim that the matter is now escalated. When they are opening the account they are quick to respond, it's immediate in fact. I am being held hostage!! Why am I being prevented from exercising my rights in this manner? It's seems like the call centre agents are trained to give the run around to keep me bound to a banking relationship that I do not want. Why is there no standard procedure on closing the account and if there is why do I not have access to it??? Someone help me be free!!!!