Complaint: I want a full refund of money due to me

I took out a cellphone contract with Altech Autopage on 26 August 2013 for an amount of R261.00. All along I was paying the exact amount. I received my statement in April 2015 for an amount of R523 and that to me was not on. When I took out this contract my request was that I want a limit set on it and I do not want to pay more than R261. For all these months I just paid R261 and are only told when I query about my account of R523 that there is no limit on this contract and the additional charges is for data usage. I have never used this sim card permanently in a phone I only used it to use up the R100 airtime that I received. My statement for May came and it is adding up to R414. Why only now after all these months of paying R261 my line is open for data. I have not been informed about this and neither was it my request on the day I signed the deal. My query is still pending with Altec and when I phoned the call centre the phone was dropped by a lady called Dinah. So sad to receive such service after being committed with this contract for nearly 2 years and the first question they asked me at the branch when I went to query: Would you like an upgrade???? I felt like....