stopping billing me

I cancelled my contract reference ***. my contact ended in October therefore you should only be debiting the +- 42 rand you charged on the contract for 500mb but you are adding packet switched data call charges of an amount I have never seen throughout the lifetime of this contract. Whats worse is this data stick is no longer in use for the last 6 months and has been sitting in my bottom drawer and therefore you have to right to debit my account for these bogus amounts for a service that has clearly not been used or touched in a long time! since the contract was cancelled on the 5th of november I expect no more charges from you and I want these mysterious shady high switched packet data calls that have sprung up on my statements for the last two months removed from my contract immediately.