You're allowed to laugh louder when it's their mistake and they scold you.A local burger joint put out a bunch of flyers with my home number rather than theirs they transposed one digit.
After about the hundredth customer of theirs trying to place a order i started answering with "our kitchen is closed due to a slight rodent problem we should be reopening in a couple of weeks".
Eventually a staff member got wind of the snafu and dialed me up and tried to give me a piece of his mind. I just laughed at him until he hung up.