Can't get a free drink

I'm a truck driver & I stop in ohio always to get fuel. I spend up to $600 each time for fuel. Sheetz has a VIP card just for diesel use, they claim we can get a free drink if we purchase 50 gallons or more. Well I go in to receive my free drink & use my green VIP card & nothing. Cashier says I gotta pay for my drink, I ask bout the free drink says they don't do that anymore. Even tho signs on the pump advertised the free drink. Like come on Sheetz, us drivers spend alot of money at your business & we can't even get a fee drink. Geez