Bought 2018 Mazda 3 and after a few months the brakes vibrate between 80-100km/h. Gone by dealer they said they serviced and still same issue … a year later serviced the vehicle and report the same issue and they now telling me to pay replacement rotors. This is cheap material from Mazda and especailly for a vehicle they call fully loaded.
Too late now, should have elevated it to corporation level when your dealer first failed to correct the problem. That and this sounds more like warped rotors rather than caliper problem.