Brake Disc Caliper problems of the 2014 Ford F-350

Since I bought the truck in may of 2014 I have experienced uneven braking, meaning most of the time when I brake, the vehicle pulls to the right hard. Less so on the left. On August 6th, 2014 I took my 2014 Ford f350xl super duty to varney Ford in newport maine to have the vehicle looked at. They replaced both brake calipers and pads. I drove the my truck to tennessee on August 15th, 2014 with our 16,000lb 5th wheel camper on the back, during the trip I had to do 2 emergency brakings in 3 lane traffic. The truck lurched to the right both times and I had to fight the wheel to keep the truck straight! it kept doing it on our way back home to maine as well. It has done this for quite some time and on July 30th of 2015 I took my truck to hight Ford in skowhegan, maine for an unusual noise in the drive line. They put the vehicle on the lift and checked everything out. The mechanic brought me to the truck that was on the lift and showed me the excess brake dust on the rims. He asked me to try to turn the right side wheel, it was hard to turn. He told me that this is where the problem could be. The left wheel turned without effort but the right side was stuck. I told the mechanic of the problems that I have with braking and that it pulls hard to the right. They checked on bulletins and there is one bulletin on unusual braking on these vehicles. This is the 3rd set of calipers put on this truck and still the brakes are pulling to the right. I am heading out to tennessee on August 14th 2015 and I am quite certain that this problem will occur again. The day after having the brakes "fixed" for the 3rd time the rims are covered in excess brake dust. Not only is this slowing my vehicle down to give me lower mileage it is also a safety hazard if I have to brake hard again on a crowded highway and slam into a few cars as well. What happens then?.