Expired contract should be just that, not an excuse to ********ly squeeze out more money from us

I have been trying to cancel a device contract which was meant to end January 2023. But for whatever reason they still keep debiting me for a contract that has already ended. What sets me off even more is the fact that I get atleast 3 calls a week from Telkom asking me to renew my contract yet I keep telling them that I've already cancelled that contract and do not wish to continue with it. Yet I keep being billed for it. I was told to go online and cancel using the Telkom app, which I did just that on the 28/02/2021, reference number ***5. It shows that it has been resolved yet funny enough I just received an emailed bill that reflects that i am still being billed for a supposedly expired and cancelled contract. Firstly it seems like I'm being forced to continue a service which I am massly dissatisfied with, because I get called each and every week to renew my contract even after I keep telling them that I have cancelled it and do not want to renew it based on the appalling service. Now I request Telkom to, as I have been requesting to cancel my supposed expired contract and stop billing me for something i am not in use of for Petes sake. If not I will pursue this further. I took out a 2 year contract, not an indefinite contract