Brake Disc Pads problems of the 2014 Mazda CX-5

At times the breaks become unresponsive to pressure and the pedal goes all the way to the floor. The breaks have to be pumped it order to get them to catch. So, I took the car to a repair shop and they changed the break pads and bleed the lines. However, after a test drive the issue happened to the mechanic again. After checking the break system again, they found that the vacuum pump is malfunctioning. There was a recall for other Mazda Cx-5s in my model year. But my VIN number does not fall in the recall. My auto repair person stated that this is something that shouldn't happen, and is extremely dangerous.

I have owned this vehicle for three years and the power brakes have failed three separate times. Each time this happens the pedal is extremely hard to push and will not go down. Each time I was driving in city type traffic. I have taken the car to jim ellis Mazda in marietta GA. They were unable to duplicate the problem and recommended a brake fluid flush having said the fluid was dirty. Also said I needed rear brake pads due to wear but they were fine. I did replace them with new as a precaution as I am a retired automotive technician. I will attach a photo of the pads. The car has 49000 miles on it and was purchased certified pre owned in October 2016. My wife is afraid to drive this car now since we don't know when this may occur again. Each time the brakes failed it was hot weather and the occurrence was sept 2nd 2019.

My rear brake pads had to be replaced with only 33000 miles on the car. The front ones have not been replaced yet. There is a recall tbs 04-003/14 on the brakes but Mazda did not honor it because they said the service manager said the pads wore out evenly. If defective they should wear out unevenly. Huh? why did the brake pads wear out so fast?.