Help, Telkom does not cancel contracts

I am absolutely at my wits end. I cancelled my contract with Telkom approximately 5 to 6 months ago but they are still taking debit orders off my account. I have contacted them several times to no avail. They keep telling me I have to come into telkom for assistance, which I did on numerous occasions, with very poor or should I say lack of service and very rude, to be told that they can not assist me, and that I have to do the cancellation on the Telkom App, which I have also done but to no avail. I tried chatting to an agent on the app, but because my typing was too slow for her (I did not respond in a matter of a few seconds) she ended the chat. I do not know what to do anymore as this is several thousands of rands which have now come off my account for a product I don't even have anymore. Can anyone assist?