1999 Honda Civic brakes problems

When stopping vehicle makes noise from front brake, like grinding metal to metal noise. Also, vehicle experiences extended stopping distance. Dealer has tried replacing pads, cleaning dust and machining front rotors, but the noise still exists.

1. My son drove the 99 honda civic ex on a residential area and merged into the main street. My son pressed the brake pedal to slow down approaching the intersection but it suddenly accelerated, crossed the intersection and hit the tree across the street. 2. Even pressing the brake pedal, car accelerated it self and could not stop the car on time to avoid hitting the tree. Luckily, there were no death or personal injuries. 3. Car had extensive frontal and engine damage and can not be repaired.