Disappointed

I have a contact with MTN for my phone and modem, my modem contact ended in May I only got around to cancel it beginning of August which was done.<br> On the 1st of September they debited my account with the amount of R1150.00 which was shocking as my payment for both the phone and modem is R348 which is the amount they have been debiting since I had the contract with them, and I have all the statements from that time that they have been sending me.<br> <br> I called the contact centre and they told me that I was being billed as I over used the data since July, my question was why am i being billed as my contract was R89 1GB TOP UP I should not be on billing i did not sign a contract for a billing account.<br> My modem is still showing that I still have 2GB remaining and when I have reached the 1GB mark it does not let me go on the internet.<br> <br> If I was on billing why did they not send me statements of the amount of data I was using for all those months, why only now when I cancel my contract?<br>