unauthorised debit.. overcharge

Unauthorised debit for payments over two months. Between July and August Multichoice debited an extra R 516.70 from my account and regardless of numerous calls and emails,no one has come back to me with an answer. I've sent bank statements showing the over charge more than once, emailed the consultants who promise me feed back, call Multichoice more times than I can remember, and even emailed the Mulitichoice customer query, but I get absolutely no response from them. All I require is a refund of my money but all I hear from the very unhelpful and sometimes abrupt consultants, is that they can't do anything besides escalate the issue. I just want some kind of feedback from them but unfortunately the service from Multichoice is beyond pathetic!!