MTN BAD SERVICE

I have struggled for almost a month with my contract amount to be fixed and I am not someone to complain as I myself work in customer service. Eventually it was fixed cause they over charged me for two months. I have phoned the Claremont MTN store heaven knows how many times. The agent(Zaid) I spoke to is always busy and almost never gets back to me. I phoned today once more and the gentleman who answered the phone told me the agent(Zaid) that helped me is busy and they are very busy they will call me back later with an attitude. I asked for the manager on duty but he/she is also not available when I call. Apparently the mistake was made by the billing department and frankly this is not my problem. No one gets back to me and this is beyond frustrating. Money is not donated to me I work for my money, so I need my account to be credited but no one gets back to me. I am fed up. Please resolve this ASAP or I will be taking this further