Telkom making money out of clients who cansel their services

I attempted to cancel my service with Telkom a few times, unsuccessfully. The last time was more than a year ago. They provide and is not willing to provide me with any confirmation that it was cancelled. Due to the fact that I assumed that the Telkom employees actually did their job, I stopped paying for the service I do not use. Then I went to the Telkom branch in Park View where the person there showed me that I owed more than R3000 and I HAVE NO PROOF that I have asked for the service to be cancelled. I Started paying of the debt of which I made the last payment on 20 August 2019, based on the last statement I received from Telkom on 10 March 2019. This week, receive a email from debt collectors telling me that I owe Telkom R1500,09. So Monday afternoon after work I went to the Telkom branch at Irene Village Mall where a very friendly gentleman showed me, on the system that I am in credit with R100. This morning when I started up my computer I received ANOTHER letter and Invoice from the debt collecting company showing that I NOW suddenly am being charged for services by Telkom AGAIN up to now for which I did not ask, did mot use AND HAVE ASKED TO BE cancelled numerous times!! I AM FED UP with Telkom. A few years ago, my husband closed a business that he had, we battled for 3 years to get Telkom to cancel the service. It appears as if the only way Telkom can make money these days is with charging ex-clients for services the do not provide to them!!