This didn’t happen to me, but I think I read about it somewhere on the internet. I’m not sure, it’s been a while.
A guy went into a motor sports shop, grabbed a mini dirt bike from the shop floor and wheeled into over to the desk. He said he’s purchased it a few days ago and it was running funny so he wanted to return it. The cashier asked him for a receipt to which he replied that he didn’t have it on him. The cashier informed him that he can’t return the bike without a receipt. He apologized for his inconvenience and said he’d come back in a few days with the receipt. He wheeled the bike out to his truck where another employe helped him load it into the bed and he drove off with his new bike. I believe they caught him when they went through the security footage but it’s still pretty clever.