Two Scams For The Price Of One

(A customer comes up to my till and drops four items onto the belt. I recognise them as being in a “Buy two, get the third free” offer. Already, I know what he is trying to do.)

Customer: “I’m buying those two and it gets me that one free, and because I’ve got that one and that one, I get the other one free, too, right?”

Me: “No, sir. The offer is that you have to buy two to get the third free.”

Customer: “I am, and because I get that third one, I can add it to one of those and get the last one free, too.”

Me: “No, sir, it has to be two separate groups of three items; we don’t allow you to overlap and use the same item twice.”

Customer: “Why not?! You’re just trying to get more money out of me!”

Me: “Well… Yes, sir. We’re a shop. That’s what we do.”