Benson Citgo

WARNING!!! The diesel pump at this station overcharges!! I stopped on road trip with family and filled up despite still having 5/8 of a tank. The truck has a 29 gal tank so I figured I'd need 10-11 gal. I pre-payed $40 just in case and filled up my truck but I ended up pumping 16.1 gal which seemed odd. I track fuel consumption on Fuelly so I entered the data and it said 12.2 mpg for 100% highway while the truck computer said 17.5. It was blatantly obvious that the pump was overcharging. I spoke to the woman working who knew nothing and said her boss could give me a call but wouldn't provide his phone number. I've placed a complaint with Citgo but I'm afraid I lost $15-20 today.