What we have here is a failure to communicate

So I was in the waiting room while Pam was having a test for her acid reflux (test showed no major problem, only a couple of minor ones) and needed to visit the mens room. I looked in the hallway, didn't see one, so went up to the desk. A nurse/tech looked up at me, and I said "Excuse me, can you tell me where the mens room is"?

Nurse: You need to sign in.

Me: I'm not a patient, my wife is, I just need to know where the mens room is.

Nurse: What's your wife's name?

Me: Pamela M-H, but I just need to know where the mens room is.

Nurse: *looks at chart* Your wife is still undergoing the procedure, can you have a seat please, and we'll call you when she is finished.

Me: I'll be glad to have a seat, but can you please tell me where the mens room is?

At this point someone doing paperwork stood up and told me where I needed to go. Good thing, because shortly they would have needed a new nurse, after I had finished ripping the head off the one I was talking to.

What do you do when someone is *obviously* not listening to a word you are saying?