CELL C failure to action client request to cancel account and proceeding to list client on a credit bureau unfairly

I opened a contract 2 years ago and have always paid my account on time. I then proceeded to give notice to cancel my contract as the contract had come to an end. CELL C nevertheless proceeded to place me on a month to month contract against my will and furthermore proceeded to place my name on the blacklist purely because I refused to pay a month fee which I had not requested for. I expressed my intention to cancel the contract which I deem to be sufficient enough. There are staff working for cell c who have no appreciation of any of the clients requests and historical payment activity. It seems that because CELL C deems itself a giant that not actioning client requests and thinking it is fine to continue to bully clients into paying accounts which they did not ask for is fine. I think the behaviour is absolutely disgusting and completely inappropriate. Similar to day light *******. You proceed to advise CELL C of your intentions, log complaints and responses and nobody cares. The manner in which they respond is with the use of the bullying tactic of simply proceeding to load a clients name on the blacklist seems to the the solution, not applying their mind to understand whether their actions are justified or not. I cannot believe that this is the behaviour of a huge organization such as CELL C and it is extremely eye opening. Never forget the a company is as good as its clients and behaviours of this manner will result in less clients and shrinkage of your business.