Telkom, a bunch of ******* & *****s! Cancellation not fulfilled.

I cancelled my Telkom land line in June 2018, as I was renting, and moved out of my home at the time in July 2018. I allowed billing to continue going off my account for June & July 2018. When they tried billing me again August 2018, I stopped and reversed my debit order through my bank. They continued to bill me, my latest bill has just come through for Dec 2018. My account is canceled. I have been emailing, I have DM'd via Twitter with them multiple times, I have phoned them, again today, where I spoke with a guy who confirmed my account was canceled only in Aug 2018 from their side, and that they will continue to bill me monthly until I settle - this is blatant theft, accruing billing until the day they finally get me to pay over money to them which I do not owe them, nor are they entitled to. I am at my end with Telkom. I have submitted multiple complaints, I keep getting dispute references, but nothing comes of it! What am I to do? If this was a individual, they would have been prosecuted by now, but Telkom, they get away with it! How?!