billing system and cancellation derpatment is just messed up

I cancelled my contract in November 2017 and im still being debited for the something I don't even use and when I took the contract I was told the amount I was going to pay and when I received an invoice I released that there were things that I didn't knew about that were added on my contract

Telkom is just a money making scheme and I will never take another contract with them ever, since I took the contract that's when the problem began. So last month I reversed the amount they debited on my account and this morning I get a surprised that im owing them closed to a R1000 including the R200 for the rejected payment

I mean I cancelled that stupid contract 3 months ago and I kept on sending them cancellation letters and nothing is happening I am so fed up with this nonsense of them im enough, actually I hate them I regret why I even when to them