Ed's Unocal 76

I stopped at this gas station to buy an energy drink. I saw that almost every brand of energy drink they sold were on sale. I selected two drinks that were buy 2 for $4. When I went to pay the cashier, the cashier rang the drinks up as regular price without the discount. When I asked about the discount the lady seemed confused and attempted to persuade me that I had the wrong drinks . That the drinks I picked didn't qualify for the discount. When I explained to her that they did, she still insisted that I was wrong. Now she said that the reason the discount wasn't applied was because I didn't have two drinks with the same flavor. At this point I didn't want to try and explain myself any further and picked two drinks that were the same flavor. At this point the cashier had already ran my credit card. I asked if she reversed the charges and she showed me a receipt where she voided the initial charges, but not a receipt showing my credit card number and the charges being reversed. She insisted she reversed it. I didn't attempt to argue with her anymore I knew that the charges weren't reversed and that I would have to check my credit card statement for a double charge. Sure enough there was a double charge with no reversal. Bad business practice and misadvertisement to the consumer.