Brake Drum Wheel Cylinder problems of the 2011 Toyota Tacoma

I was parked at a trailhead, at about 3500' elevation. After the hike, as I maneuvered the truck around the parking lot, I realized that I had little or no braking ability!! I slowly drove around to see if there was any fluid on the ground where the truck had been, and there was no fluid on the ground. There were no warning indicators on the dashboard, and absolutely nothing indicated any trouble with the brakes. However, I discovered, as I continued to drive home, that the brakes had failed and I was unable to stop the truck with them. The truck had to be towed to the dealership for examination and repair. Subsequently, the dealership replaced the master brake cylinder. The replacement master brake cylinder also failed!! (during testing, not while driving. ) the third master brake cylinder was put in, and seems to be fine now. Despite detailed correspondence to them, Toyota corporate failed to acknowledge the problem, and refused to discuss compensation. They also did not communicate with the dealership about our correspondence. Fortunately, the dealership took very good care of us.