Brake Disc Caliper problems of the 2018 Ford Explorer

Driving the vehicle at about 40mph coming off a bridge, I hear a rattle coming from the rear of the vehicle as I brake. The brake fully depressed applies virtually no braking power. I was able to bring the vehicle to a stop by pumping the brakes as well as using the emergency brake. I walked around the vehicle to see what was going on, I noticed fluid near rear passenger side tire. The rim and street had brake fluid all over it. Upon further inspection part of the brake caliper assembly was hanging behind the rotor. The car was towed to a Ford dealership that day. Was not inspected same day as service was closed for the day on Saturday. The vehicle was inspected by dealership on following Monday. I was told the bots that keep the brakes in place were missing. The brake in question was inspected by a Ford dealership previously as there were odd marks on brake rotor, the dealership that there were no issues and no service on brake.