Brake Loud Noise problems of the 2015 Chevrolet Equinox

I just purchased a used 2015 Chevrolet Equinox from rick hendricks chevy duluth. Since I have purchased this vehicle, I noticed loud noises coming from the brakes when applying pressure to stop the vehicle. Not only that, but while driving it makes a knocking sound. I was told by one of there mechanics in the service department that it was ok! the Equinox is known to make a little noise while driving. It has been to there shop over 3 times for several days at a time in less than a month and still the problem continues. They explained everything they fixed to make sure that the noise was gone and the brakes were in good working condition. When I asked for proof they were unable to provide it. I am not a mechanic but I do not believe for one minute this vehicle should be making any noise at all let alone noises when you apply pressure to the brakes. I have reiterated over and over again to rick hendricks chevy duluth that there is a brake issue going on with the vehicle that could possibly be deadly and I was told there is nothing they can do. I try to limit the amount of driving I do to important places only seeing as the noise is still there.