My brakes start to squeak very loudly after I drive for about 10 minutes. I brought my car to the shop two days ago, and they said everything was fine with the brakes, and the noise was being caused by brake dust. They got rid of the brake dust, and the brakes didn't squeak for about an hour, but now they are jus like they were before i brought the car to them. Do you have any suggestions about what it could be?