Charged for Itemised billing

I have a contract with cell c, and I have just notice that the amount they debiting every month is not the same that is written on my contract... As I phoned to enquire I wwas told it for Itemised billing. Who did you discuss that with? how can you charge me for something that I'm not aware about? Something that you dont even send to me? and how long have you been charging me? because i took this contract in 2010 and I'v been upgrading ever since.. I need someone to answer these questions and I want my money back.<br> <br> Disgusted and angry.