I was parked at a diesel pump next to a van and travel trailer when the rookie driver, borrowed his brother-in-laws camper, decided to try and back out of the pump area to no avail. I told him he would need to pull forward to exit and I would be done pumping soon. He must have been in a big hurry and left pulling straight ahead and the turning left watching only that he did not hit the pumps. As he turned left and the rear end started coming towards the back of my truck I began to yell as loud as possible, DW jumped out of the passenger seat and began to yell stop. I was banging on side of his camper but he continued on until he heard all of us plus other patrons yelling to stop. Bottom line close to $4,000.00 damage to my "17 Ford 250 lariat 6.7L diesel. Sick to my stomach.