telkom accounts dept a waste of time

I am on an unlimited call option with telkom but I was charged for calls in my April.bill. I complained to overport branch but no credit was passed. Once again I was charged in may statement. I complained at overport branch once again. its gone almost 4mths and still no credit has been passed. I am now damn frustrated and would appreciate it if management could call me to sort out this issue asap. Nasreen ***