Unable To Read Sign Language

(I am a customer. As I am walking into my local store, I notice a giant, hand-written sign on their door, all highlighted. Apparently, the card readers on their pumps are down, customers need to prepay inside, and they are sorry for the inconvenience. There are also notices on all the pumps. I am in line when I hear this exchange:)

Customer: *to cashier* “Are your pumps broken, or what?!”

Cashier: “No, sir. They just can’t take payments at the moment. I’ll be glad to prepay for your gas here.”

Customer: “Ugh, fine. You really should put signs up, though.”

Me: *chortles to myself*

Customer: “What?!”

Me: “Um, there’s a huge sign on the door saying that.”

Customer: “Nobody reads those! There should be signs on the pumps!”

Me: “Sir, I didn’t even buy gas and I noticed the signs on the pumps.”

Customer: “Shut up.” *followed by the evil-eye and silence*

(I don’t know how the staff can keep it together like they do and keep from slapping the stupid out of people.)