POOR SERVICE

I phoned Cartrack to test for my Vehicle they said they will call me back i called 2 times they said the something month end i received a call that i owe them i did not pay them because they did not assist me only to find out there was a problem with my unit and a request has been sent to be fixed no 1 came and i did not know i am siting with the unit that is not working but they expect a payment from me