Cell C Deducts amounts not stipulated in Contract

My wife renewed her contract with Cell-C ,Before the contract was renewed and still on the old contract , they were deducting unauthorized amounts off her accounts,on complaining they promised that they would rectify same.They appeared to have done that but it continued, it was apparently for a ''GET IT'', whatever that is, it was not requested, it is happening again with the new contract, The contract amount is R89 per month, she has never paid that, it is R140 plus minus a month.She never received a refund in spite of assurances that she would and the practice would stop.She has a list of reference numbers relating to all these calls and visits to Cell -C,but to no avail.When she requested a cancellation of this contract due to breach of contract on Cell-C's part she was told she would have to pay R800 odd for that privilege, Had they not heard of the CPA,but in all fairness it is not Cell-C but THE *********** STAFF who happen to be the front line of the company and who when you phone,is always a different person.<br> Should this not be resolved satisfactorily with a refund of all overcharged monies refunded,then this contract will be cancelled, and I will do the same.