I would mention this to your BMW center. The BT/Assist TCUs are coded with the VIN number of your car. It sounds like they have entered the wrong VIN ... which is very odd ! Recoding will fix the problem.

As a test, when you pair your BT phone with your BMW, your phone should see the device called BMWabcde .... where abcde are the last 5 digits of your VIN number !