Vodacom doesn't want to cancel my contract which ended a long time ago

I have been trying for a long time to cancel my vodacom contract. I started at the month it was ending - March 2018. I called 1958, was called to send an email to the cancellations which I did. I got a standard response to say I must call 1958 again to cancel. Which I did and was told again to send email. After back and forth of no one wanting to cancel my contract even though it was at the end, I decided to stop payments as clearly no one wanted to cancel my contract. Now recently i find out apparently I owe Vodacom. I tried again 1958, Nhlanhla referred me to Buhle in collections, Buhle(who was very rude, practically put the phone down on me when I demanded help) referred me back to 1958, where I got Buhle who also said she can't help me. They also can't give me a breakdown of what makes up the amount they say I owe and on-one apparently has the capability to cancel my contract. At the same time the so called amount owed is increasing. I cannot understand how this simple request can drag for so long, if I owe money, I need a statement. As i'm willing to dispute this as I have emails confirming in writing that I was cancelling my contract. I also still want to cancel this contract. I cannot afford the back & forth anymore. Can someone who is able to help please contact me and help get this resolved!