over charging

I took a contract on 5 December 2014 at telkom.it was an Asus phone pad and the amount was R89 per a month. Ever since I been billed R107.90 every month. I queried it and did not have any feedback. Finally a feedback came stating i been charge for my account been posted which i have not received from the time my contract has been taken. I want a refund for these past nine months! This is utter ridiculous. I even called the call center. I ve been pushed from one person to another at both francie sun telkom.i want my refund.