Process Server Incorrectly Coming To My House Harassing My Wife

A process server has come to my house twice now when I am not home and stood outside for an hour repeatedly knocking at the door (we have a camera). He left a note with a name on it that we do not know (we are renters). My wife called him and told him the person does not live here (idk why she thought that was a good idea). The process server is now calling my wife repeatedly and harassing her. I told her to just call the police but what can we do? I don't even know the person they are trying to serve and they are getting more and more aggressive my wife is scared and I am not home right now.