Get More Cancelled, Cell C still billing me monthly

I am so dissapointed in the service of Cell C. Since 2016 I have been phoning Cell C and requested that they cancel my Get More on my account because I have never used it before and never will, every time they said that someone will phone me regarding the matter but no one phoned. Eventually a few months ago I got through to correct department, they assured me that my Get More is cancelled and that I wont be paying for it. As my Cell C is going off with a Debit Order, I don't always check my statement, this month I decided to check it and guess what??? I am still paying for Get More. Why is Cell C taking my money monthly? I demand a refund for all the months that i have been paying! I really don't have a problem changing networks if this problem is not resolved!!