Unhappy customer

Hi, I bought a tablet from MRP Mobile for R129.00 a month. This was confirmed with me on the call when they sold me the tablet, but my first debit was R460.69 and the balance on the account is up. I was confused so I reversed the debit order after a few days an agent call me asking about the payment I explained why I reversed the payment.According to her there was \value added"benefits on the account???? I did not authorise that this should be added so I told her to cancel those benefits and she told me she did"