Brake Squeaking Noise problems of the 2015 Jeep Renegade

I bought this car in April 2018 with 15,000, about a month after driving it started making squeaking noises when I braked, when I brought it in they told me it was fine and that it was possibly a rock. It didn't stop, so I brought it to another dealer who couldn't find the issue, then I brought it back to the dealer I bought it from to get a tire key and they replaced the brakes for free only it didn't fix the problem. When I brake it sounds like metal is crushing together, it is the worst sound and it is extremely unsafe,so I brought it in again, and when I brought it in this last time I made a service tech get in the car with me and he agreed that was not right and then the next day he calls me and says nothing is wrong everything looks perfect. They then tell me they test drove the other Renegades in the lot and they all make the same sound when you brake, clearly something is wrong with the vehicle.