I've been working at a movie theater for almost two years.
I've seen and dealt with a lot of shit with customers, but there is nothing more infuriating than a customer who isn't paying attention and does this.
C is a customer, M is me
>*customer walks up to my till*
>M: Hello, welcome to (movie theater)! What can I get for you?
>C: Can I have a regular popcorn and a regular drink?
>M: Absolutely, is that everything for you today?
>M: Alright, so I have a regular popcorn and a regular drink. Is that everything?
>M: Your total is (whatever it costs, etc).
>C: I'll pay with a Credit Card!
>M: (points to card reader) Go right ahead!
>*proceed to get pop and popcorn for customer*
>M: Would you like a receipt?
>C: No thanks...
>M: have a great day!
>*customer looks at me funny*
>M: ... Anything else for you?
>C: *I ORDERED TWO DRINKS, WHERES MY SECOND DRINK?*
>M: Oh, im sorry I must have misheard....
And you get the idea. However, not only did I confirm the order *TWICE* with the customer before payment, we also have screens in front of our tills that show the order.
That was *THREE* opportunities to correct me if I actually missed something, or to add something to the order.
Instead, the customer is worried that they are going to miss the latest advertisement for a car, and are in a hurry for some reason.