Continuing Cell C saga

Now 6 months trying to cancel a data account. I told Cell C that I wanted to cancel. Paid my cancellation fee. Emailed them a copy of proof of payment confirming I wanted to cancel. Now they invent a new obstacle; I was supposed to phone them as well as confirming by email. I presume this added hurdle was designed to make me give up and continue with the contract. So poor reception, multiple dropped calls and poor customer service and for this we pay one of the highest rates in the world.