Brake Master Cylinder problems of the 1999 Buick Regal

My wife?s 99 Buick Regal, with less than 31,000 miles, bought new 12/99, suddenly started to lose brake fluid during the first week of September. We could see no obvious leaks but each time we test drove the car, a small amount of brake disappeared from the master cylinder reservoir. Since the warranty ended last December, I called gm special policy adjustment program and I was advised to take the car to the closest local gm dealership and have the problem diagnosed so repair requirements and costs could be determined for any possible special adjustment. I called the local sun dealer on 9/4, but I was politely told don?t come here because I didn?t buy the car there and they didn?t want to get involved in any cross warranty issues (despite the fact that I was willing to pay for their time). I took our Buick to a trusted local repair center and it was promptly determined there was a rusted and leaking metal brake line, other severely rusted (but not leaking) brake lines and severely pitted, corroded and rusted rear brake rotors. The private garage replaced the rusted & leaking brake lines, rear rotors & brake pads for a total cost of $412. 31. All replaced parts were given to me at my request. On 9/6 I fully documented what had transpired and submitted it to Buick?s online customer relations, and was assigned request # 1-137192830. I was told via email Buick?s gm special policy adjustment program would follow up. On 9/11 I spoke with a gm's special policy adjustment program person, explained what had transpired and was told only the service manager at the servicing dealer could approve any reimbursement outside of the warranty. They would notify him of my claim. On 9/12 I called the service manager (who seemed very concerned because of the car?s low mileage) but he couldn?t do anything without the area service manager?s approval. A few days later I received a voice mail saying the area service manager wouldn?t get involved or approve of any reimbursement.