Lack of customer support

I have been with their service for the longest of time, i payed my premiums without fail. Years later I realised my car battery was always drained and had to replace if twice, took my car for diagnostic and only to be told it’s the tracker that’s causing it, i asked them to come and fix the problem and only for them to ask more money from me in order for them to fix their own faulty device. I declined to do and cancelled their service with last payment to be debited on my account, they failed to do that nor to assign a technician to come and remove their device as per my request. I have been struggling with my car since July and yet nor technician came to assist me with removing the device, but their account department has been hounding me ever since for 150 rand while i have been jumping starting my car since I cancelled their service, their service is repelling to say the list.