Nissan Altima 2000 - brake pads replacement

I have a Nissan Altima 2000 with 78414 miles on it. On 06/14/07 I went to the Nissan Dealership to get it checked because every time I braked my car screeched. They told me the drive belts had to be changed. They also checked the brake pads and didn't change a thing. The car was not put back together correctly, so when I drove it out of the dealership and was about 2 miles before I statrted accelerating; the car refused and was stopping and moving. I went back to the dealership and they told me the Coolant wire were not making contact as they should therefore the problem; they gave me an rental car and asked me to return the next day to pick up the car. I told them my car was going to be idle for about 4 months because I was travelling abroad. When I returned, 10/06 I started driving again, the car still made a still screeching sound and on a recent trip to Chicago from Indianapolis the sound became louder and louder. I went to the dealership and they told me that the front brake pads are 0% and that the brake is cutting into the rotor. Seems like it is time to change the brake pads. I am not sure though. Besides, I am concerned whether the dealership gave me the right advise the first time around? Help me understand what I need to do next. The dealership under discussion here is Hubler Nisaan in Indianapolis.