Quick to take your money or charge you double

So angry with cell c. I have not received my statement since july and my last contract with them is now due for upgrade/cancellation. I just called them to cancel the contract and was informed that my last debit order will now be double as i am month to month and the special ia no more valid. The more i ask why i was not called and offered a upgrade the more i get told it is not their job to know when my contracts need to be cancelled. Quick to offer you a contract and take your money..... now i must pay double because they are slack in sending paperwork. All contracts now cancelled and they will never hear from me again