poor after sale service

I recently purchased a Nissan Magnite with an extended warranty as well as a service plan. Soon after purchasing the vehicle, the car started making a horrible squealing noise whenever I braked. I then took the car in for a service. This changed nothing - the brakes were still squealing. the noise then started happening even though I was not braking. I then took the car in again and the dealership informed me that this is a common problem among Magnites. Why this was not communicated before is appaling. The dealership then told me that the brakes would take 2 weeks to source. Two weeks passed and I then asked that I get a replacements vehicle as driving a round with a faulty car is not safe. suddenly, new brakes became available. Needless to say, even with the "new" brakes the car has gotten worse. I then sent through a complaint to Nissan and NO further action has taken place. Nissan clearly does not care about the safety of their drivers.