I spent many years as a window clerk in the main Post Office in our town and I ran across some doozies over the years. One of my favorites used to happen regularly before we were authorized to accept credit cards.
Customer; "Hi. Do you take Visa?"
Me; "No sir. We're not set up to accept credit cards."
Customer; "Oh. How about Mastercard (Discovery, Diners Club, Carte Blanche, etc)?

troll