Complete Failure to uphold their end

I upgraded my cellphone contract a few months ago. One of the features of the new contract was that I get to make free calls to other Telkom Mobile subscribers, at no charge to me. When I pointed out to them that I was being charged for that feature, they removed it from my account, and now I'm being charged for all calls.<br> <br> I have reported the issue to them multiple times. The call centre says it has to be resolved by the \back office"team. The call gets closed each time without being resolved. I have now not paid my bill for last month because it is in dispute"