Handed over for premiums if Tracker was cancelled

I do not have a contract with Tracker and are on a month to month basis. After canceling my tracker last year I received a call from an attorney today, that I owe them +R700. After taking MY time and using MY cost, phoning Tracker, the lady just say, sorry, we do not have record for your cancelation and it is my work to go and investigate why they do not have this request and proof it. Tracker is just patronizing me and I have much more important things to do to go and proof and investigate. Apparently is is my work to do that. You should have canceled my month to month Tracker and I expect you to do so backdated now. I am not liable for backdated premiums if you are *********** of actioning a simple cancelation request in 2020. If I am black listed for these premiums, I will resort to legal action.