Genius at work, I received 10% discount card provided by Mirage Hotel LV, I handed cashier and she took the card and handed back to me. Receipt didn't show 10% off from total prices. Second process, she takes the card run through card reader and said okay I took off 10% off.
Third process, I did ask where is my money and she said I took off the price showing the transaction paper. A man behind me said to her you owe him the money. Finally light cane on, she retyped the entire process again with my two bucks back.