Did you know that if you buy gasoline from a dispenser equipped with a vapor recovery nozzle, you are being charged for the amount of fuel being pumped from the gas station's tank, but the fraction that volatilizes between the station's tank and your vehicle's tank is returned to the station's tank?
So, yes, you could go into the store and try to browbeat the attendant into giving you a refund for the amount not actually received, but of course you will need to include in your calculations the $0.001 that retailers subtract from their prices to make the cost seem less, as well as the temperature and pressure of the fuel and the exact formulation of the fuel to get the right vapor pressure under those conditions.
After a few years of educating the attendant about stoichiometry, thermodynamics, and organic chemistry, you might convince him or her that the gas station owes you a fraction of a cent. If he or she is feeling generous, you might get a full penny from the penny cup (congratulations, you foxy devil). Or you could just assume that the vapor would have been lost to the atmosphere without the nozzle boot, and that it is preferable to put it back into the tank for reasons that have nothing to do with the price of gasoline.