Unhelpful staff and endless stuggles

How long must one be struggling to remove a tracking unit? Little backround. I’ve bought a car in 2021 from someone that had a MX3 tracker fitted, long story short she told me the tracker was deactivated but not removed. So I didn’t care about the unit and fitted a new one with my preferred choice. In the beginning of this year my car left me in the middle of the road took it to mechanics nothing was wrong with the car a few weeks later same problem but nothing was wrong. I ended up doing everything in my car brand new but still had the same problem every now and then. When i Called Matrix in June to find out if they can remove the tracker they told me its still active and can’t be removed and I must call the old owner to cancel it. Now i ask you why is it my problem to contact the old owner asking them to CANCEL again. But i did what the customer care centre lady asked me to do. They told me they would call me back but didn’t so until this month i was left with the same problem. I’ve called the call centre spoke to the lady and now they can’t seem to find the cancellation email that was send the 2nd time. So yet again they were unable to help me. I can understand there are routes to follow but for a new owner of the car i just want to get the unit removed. After a huge stuggle to get hold of the old owner she emailed yet again the cancellation email and till the 4/11/2022 still nothing heard of them and its almost 2 weeks now. For the record i have all the names of the people I spoke to.