Over charge for 6 months and counting...

I subscribed to a data contract for a monthly charge of R1059, but have since been charged a fee of R1399 each month. I have had numerous call with the guy at the shop where I signed the contract and have also shared numerous emails with the customer care department to rectify this matter. 6 months down the line I still get billed R1399 and have not heard a word about being refunded... I have been a loyal customer of MTN for more than 10 years, but this is a really bitter pill to swallow... @MTN - I hate having to do this, but you leave me no choice.