Unhappiness with Discovery Vehicle Tracker unit

I installed Discovery Tracker unit at the Sandton branch in November 2019 for 3 vehicles. It was difficult to get a booking and had to wait for each car as it was installed taking around 2 hours. The installer mentioned that the Rav 4 will have 2 Trackers installed as high risk. I questioned about the battery drain and he indicated no problem I thought this might go away since new unit and has to settle in in operation but it has not. Work was done well however on the one vehicle there is an intermittent disturbance which activates the car PDC (park distance control) while driving. The tracking device also interferes with the PDC accuracy as it sometimes blocks the sensor to alarm module which has resulted in many near misses as we rely on the park distance sensors. .Over a long weekend where car was in garage, the battery went flat. I called Discovery on one of those high call volume days for help and nobody could assist so I eventually gave up. Someone from discovery called my wife and she relayed same message but no feedback to date. Can somebody from Discovery car insurance please assist before we damage the vehicle due to PDC sensors signal being blocked by tracker signal. Unhappy customer.