******* and ********** business practices by Cell C

Had the most terrible experience. Whent in for my scheduled upgrade and found out Cell C has been *****ing from me by continuing to charge me for a service I had cancelled 4 years ago. Best of all is they flat out refused to cancel this ******* deduction from my account and told me that it is my problem and that they will not cancel "Get More" even though I have correspondence proving that I had cancelled this years ago and even got a rebate for 2 years of ******* billing. How on earth does a company get to a point where they blame the customer for their ********** practices (I specifically refer to the conversation with the call centre as the branch has no authority to actually help their customers). This will now be the third time I have had this issue with Cell C of activating "Get More" on my account without my authorization and then *****ing my money for 2 years. They are literally forcing me to change network after being a paying customer for years... Please help! Why is it so hard to get Cell C to stop *****ing my money? If at all possible I would prefer to stay a customer but if this can not be resolved not only will you lose me but I will have no choice but to take legal action.