Contract cancellation not processed

This companies service is very poor, In 2021 I tried to cancel the tracking device contract with them, sending email with out any response, through phone calls no response, last year they told me I can't cancel the contract until the agreed period of the contract has ended, that time arrived was handed over to their lawyers MBDSA and was told the contract will be cancelled as soon as I settle their outstanding amount, I made arrangements with MBDSA was told I qualify for discount to settle the amount that amount was debited from my account once off the lady and I will receive a paidup letter. To date haven't received any paid up letter, I called MBDSA requesting for a paid up letter they told me they don't issue paid up letters Telemix should send me a paid up letter, I've been calling Telemix been taken from Pilar to post, this morning I received a call from a different company NIMBLE GROUP Telling me that I've been handed over to them I owe telemix R800. For what where as I know that we don't have business any more as I paid them what was owed to them. We ad consumers are treated fairly by these companies what more should I do for this to be cancelled as it keeps on coming back. This is a ******* of monies we don't have.. DO NoT Do business with Telemix they are not professional at all. I am really angry