Poor service ever

Worst customer service ever. Unit dont work for two years. They send messages to tell us they cant get hold of us but they can send sms. We have stoped the debit order for them to contact us. Now all of a sudden after every months payment they want to give us up at debt collector for R187.00. i have tried contacted them with no answer on there phone's. I was stuck next to the road 2 years ago. I contacted my insurance for road side assistants but they could not locate the vehicle. The tracking unit was dead.