Welcome Victoria, If you are not happy with the service, then take the car back, (with a friend, if you feel intimidated by the garage), if they still don't sort the problem, then contact BMW, hopefully someone can recommend a garage for you, you do need a garage with all the diagnostic equipment. Not being nosey, can I ask what they never sorted out on your car, also you can google BNW garages in your area and check reviews to see what other people have to say about them, good luck.