Q: Van's steering wheel pulls to the left and right

My steering wheel is pulling to the left and the right. In my research and talking to friends, I have determined that the cause of this steering wheel problem is because the front brake pads are grinding the rotors. I took it to the dealership and they replaced the pads, plus shaved the rotor. It helped for a month, but then the same problem started recurring. I returned to the same dealer and they performed the same techniques as before. It still didn't help. My van had the very same problem! So, I returned to them a 3rd time and was told that my vehicle was operating the way it should. This steering problem could cause a dangerous situation. Can you tell me where I can get proper assistance to fix this?