Cancellation of contract

I recently cancelled my contract with Cell C as i took this contract out for my wife at the time and no longer needed it as she passed away. This was somewhere around August last year. After several phone calls and tons of patience i managed to get hold of one of the Cell C customer services agents. I explained that i wanted to cancel my contract of many years and i was told that i would have to pay one more installment the end of the month. She cancelled the sim card and contract (as far as i thought). The installment went of the end of October and i thought we were done. To my shock another installment went off the end of November, but i cancelled it and then the end of December another two installments went off. Once again i cancelled it and a few days into the new year somebody from Cell C started phoning me phoning me. Funny thing here is that they have 1280 spam reports on their name and because i downloaded true caller the calls were rejected. I then received an sms informing me that i was handed over for non payment. I contacted Cell C and this conversation ended up in a huge argument as i was then told that i now owe over R800 because i did not allow the payment to go through so the contract is not considered cancelled. I explained to this gentleman that there was never any mention of a second payment and why should there. His reply: I have to go to the police station to write an affidavit then send it to some legal department at Cell C so i can request the conversation i had with the previous consultant. Who is the client here??? The very same thing happened to not one, but two of my colleagues at work. Well i dont care what they do. They will not see another cent from me. This is by far the worst experience i have ever had with any service provider and from all the reviews and complaints i have read this is clearly a very *********** group of people. Simply put.