Netstar never again

I had installed the tracker from Netstar on my car in October 2019 and I continued to pay for the tracker until I was no longer using my car and I told them to cancel the monthly debits. To my surprise they told me they have a two year contract with me and I have never signed anything with them so they refused to stop and I also stopped paying the monthly fees. Which led to them handing my account to their lawyers. So in November 2020 I decided to settle this account with their lawyers since I didn't want to be blacklisted as they were threatening me. their lawyers confirmed that I have settle the account. I am talking about R200 here. Now I see their invoices and when I tell them I have cancelled it and they even handed it over to their lawyers no one seems to be responsible