Technicians refuse to remove to remove defective tracking unit depleting the batter

Although a BMW accredited technician has diagnosed the car tracking unit as defective and depleting my car's battery, the Mix Telematic technicians refuse to come and repair or remove the defective unit. After spending 2 hours and 38mins in 4 phone calls, and speaking to a series of low energy level call centre agents, Christine, Steve and Kaya, I am eventually told that technicians will come to the car to fit the unit, but may not come to the car to repair or remove a defective unit. Obviously a policy that is to the company's benefit and convenience, not to the customer's. Anyone considering installing this unit, be warned that it when it fails, you will receive no back-up.