Brake Grinding Noise problems of the 2003 Chevrolet Malibu

I bought my Malibu new in September 2003. In January 2005, I began to notice the car shuddering while braking, I took the car in and they machined both rotors, I took it in again on February 8th because the brakes were making a chatter and clank sound, they told me the calipers needed to be lubricated, I brought it back on February 18 for the lubrication. Next I took the car in for a oil change on March 29th and asked the technician to check the brakes and was told they were fine. On July 1st 05 I took the car in again because of a brake squeal and found the retaining bolt /pin on the left front caliper was missing. It was replaced as well as the bolt/pin on the upper bolt/pin due to the integrity of the original bolt/pin. On September 30th 05 I took the car in again for brake noise, and was told that both rotors were rusted, both rotors were turned and cleaned at that time. On October 12th 05 which was only 8 days later I took the car back again because the car was still making a grinding noise. When inspected the front rotors were again found to be rusty, pitted and worn, this time they replaced both the rotors and the brake pads. I took the car in on November 23rd 05 for recommended 15 max service which included a rear brake adjustment, I asked them to check the front brakes again, because they were still squeaking and they said they were fine. May 25th,06 I took the car in again for brake noise, they first told me the calipers again needed to be lubricated , but then came back and said they needed to be replaced. Now it is July of 06 and I am still having problems with the brakes. Also on July 5th, 06 I had to take the car in because the a/c and the recirculation mode stopped working, they replaced a bad hvac control module.