Appalling Service received front Discovery Insure

From late last year we have been having issues with the discovery tracker... Draining the car battery. Vw has replaced the battery and the problem persisted so a technician from discovery eventually came to do something but the it was still draining the battery as well as intermittent issues with the start stop. I called again in December and was promised someone will come out to replace the tracker but since nothing. This is such pathetic service, I would hate to think if one had to do a claim how bad the service will be.