Brake Grinding Noise problems of the 2011 BMW 328

"takata recall" I recently purchased a 2017 Nissan maxima sv and since I have acquired this vehicle I have been having problems with my brakes. As I am driving the car the brakes make a grinding noise. I have taking the car for maintenance on two separate occasion at pohanka Nissan (where I purchased the car) and colonial Nissan. Both places conveyed to me that there was nothing wrong with my brakes but either location did not drive the car. This is unacceptable for a newer model vehicle to experience such a defective issue. This is a safety hazard and I fear that my brakes will give out while my family and I are driving. I have never filled out a complaint before for my nissans vehicles but I am a faithful Nissan buyer that would like this issue resolved.