2018 Buick Encore Brakes

Have been experiencing brake malfunction on my 2018 Buick Encore with the brakes getting locked while driving. There were instances where the brakes would lock randomly and the vehicle would start slowing down during driving even with a foot on the gas pedal and I had to turn on the hazards lights to pull the vehicle on the side in order to avoid being rear ended. Took the vehicle to a GM dealership and initial diagnostics mentioned that the brake pedal position sensor was malfunctioning and would need a replacement. Agreed to replace that, but after this repair dealership claimed that there was a loose pivot in the brake pedal assembly causing the brake light to be on(Did not have this issue before taking the vehicle to dealership). Since the vehicle was not in a driving condition due to the brake light being "ON" all the time, as per the dealership suggestion I agreed to replacing the entire brake pedal assembly as well. However, the original issue was not resolved and the dealership is now recommending that replacing the master brake cylinder and brake booster might resolve the issue. The dealership has also mentioned that all these recommended repairs are from GM and my vehicle is still at the dealership.

I HAVE COMPLIN TO MY DEALER ABOUT MY CAR EXCELERATING WHEN I HIT THE BRAKES . THEY SAID THEY CAN FIND A PROBLEM , WELL IT HAPPEN AGAIN ON AUGUST 29 2019 AN IT CAUSE A ACCIDENT I WAS DRIVING ON A 6 LANE ROADWAY AROUND 330 IN THE AFTERNOON I WAS IN CRUISE CONTROL AT 45 MPH AN WHEN I WENT TO STOP THE CAR ACCELLERATED . I WAS NOT ABLE TO AVOID THE CAR IN FRONT OF ME