(Our station accepts certain gas coupons which require that the gas be pumped first, and then paid for inside the store. I’ve already instructed this customer to select “pay inside” at the pump before returning to me for the discount.)

Customer: “Alright, I’ve put $42 in my car.” *gives me the coupons*

Me: “I’m sorry, ma’am, but I needed you to select the pay inside option at the pump, and it seems that you have used your credit card outside. My computer system will not authorize this discount.”

Customer: “What!? You told me to pump my gas first!”

Me: “Yes, but you needed to select the pay inside option like I instructed.”

Customer: “So you won’t give me my discount?”

Me: “I’m sorry, but there is no way for me to ring it up. These coupons never expire, so you can hang on to it and feel free to use it next time.”

Customer: “This is outrageous! You are a poopy face mister! You’re grounded!” *storms out*