Telkom pathetic service and debiting my account for services not rendered.

Is it possible to give this company a negative rating? Last July I cancelled my data contract. Telkom debited my account for an amount of R369. Upon receiving the invoice I queried why I was billed for the month of September 2020 when I had not recieved any data. They assured me the debit would not run off I was given a reference number. The money thereafter came off my account. I called telkom once again to escalate the matter and emailed a manager Sandile Phuti who never bothered to respond. Lo and behold when I call again, my reference number for the matter could not be picked up by telkom I was assured by a consultant that someone would return my call within 24 hrs that was on the 27th of January and surprise suprise no one has called me back. This was done to me a year ago as well for my phone contract where they debited me an extra month even though I cancelled my contract. That was for an amount of R249. I never pursued the matter. How can this be done to me for the second time and how many more customers are they doing this too?