Brake Grinding Noise problems of the 2016 Mazda CX-5

In August 2016, I bought a brand new 2016 Mazda Cx-5 (dealership: wellesley Mazda). Unfortunately, the car had issues related to my brakes. On December 08, 2017, the brakes of my right rear tire locked up while I was driving in a city street (35mph zone) causing them to overheat to the point where the brake disc got red hot and smoked up, increasing the risk of my tires blowing out/catching fire due to the heat generated by friction. In addition to this being a safety risk for myself and other people on the road, this was extremely inconvenient. My car was in no condition to be driven and I was stranded alone in the middle of the night. This is not the first time this issue occured. I had a similar complaint in August 2017 where the left wheel locked involuntarily while I was driving. I was fortunate that I was able to notice the smoke before things got worse and that this did not cause a collision. Wellesley Mazda replaced the calipers, brake disc etc. Only for that particular tire, despite my repeated requests to replace those for all the tires or for at least that axle. My car has only run ~8,000 miles, I am regular with my car's maintenance and my last service was on 12/04/2017. Mazda is telling me now that this was a known issue with the calipers and there was a service bulletin for this. However, I was not made aware of the this issue and the safety bulletin. This could've been done on multiple occasions: a) when the issue with the left brake happened b) when I reported a grinding noise coming from my car (in sept or oct) c) when I got my car serviced. They were not able to detect this issue and as a safety precaution did not replace the other caliper, a decision that proved to be incorrect and a risk to me and others. There are no recalls either.