try another dealer or try calling BMW NA about the lousy service you have been getting.
Your gonna need need new brake rotors/pads/sensors - thats about a $750 job COD(when your paying). Should be free under warranty. And often the rear brakes are not far behind when the fronts are worn out. But when your front brakes start to squeak all the time... they are about half way worn out.
Depending on how many miles on your car... you could also be due for new spark plugs(covered at 45K miles). You should also have an free oil change done, pollen filter and new wiper blades - all free under the warranty.