Keeps calling and asking to speak with one of the girls who work here, even though she doesn't know him.
He ordered food from our restaurant and when the delivery person showed up, he answered the door totally nude, and then refused to pay because the delivery person was male.

Next time he calls let him talk to the girl. Let him place another order then have a female deliver it. Before you deliver call the police and have them at the door with her. If in fact he does answer the door nude again He'll be arrested on the spot and he'll forever be registered as a sex offender.