Question for people who work as cashiers?

Let's say your at work on the register. You get a costumer that is buying a big item like a 8 pack of paper towels, or a large bottle of laundry detergent. Your store doesn't give out 'paid stickers.' But the costumer buying the large item, asks for a paid sticker, and you answer him/her you don't have paid stickers. You give the costumer his/her receipt but he starts fighting with you and doesn't care that the store doen't give paid stickers....but he still wants one. What do you do?