Discount Their Math Skills

(My store is having a sale for 20-40% off. A customer comes in with a return, and she wants to purchase some more items as well. I try to run it as an exchange, knowing this will actually save her money.)

Me: “Okay, after your store credit, you only owe $10.61.”

Customer: “Wait, what are you doing? I wanted 30% off!”

Me: “I realize that, ma’am, but actually, if you run this return as an exchange, you will actually pay less money than with the 30% off.”

Customer: “No! I wanted my 30% off! Just let me return this and get my 30% off!”

Me: “Okay, I can do that.”

(I do the return and then ring up her purchases.)

Customer: “Okay, your total with 30% off is $32.54.”

Customer: “There! That’s better!”