CTLAWYER,
“My chart says that I am to be addressed as Mister Y”
Explicitly in a section for nickname/preferred name? Then yes the receptionist made a mistake, but a pretty small one in the grand scheme of things. If it’s not explicit, then that’s on the office manager or whoever set up your chart, not the receptionist who called you back.
“I was the only patient in the waiting room, so no other was delayed.”
Then why would the receptionist call out a name three more times to a room empty except for you who didn’t answer the first time? And even if nobody was actively there at the moment, your appointment got off to an unnecessarily later start, which does impact those coming after you.
“The employee deserved a dressing down, it took place in the office, perhaps the office manager should not have been so loud, or maybe the office manager wanted me to hear this.
I had complained about this to the office manager in the past.”
No she didn’t. A simple response of “Mr Y is here and ready to go back” along with a smile in response to her “Is X here?” would have politely and clearly gotten the point across. You didn’t score a win for politeness in the world; all you got was a receptionist and office manager who don’t like you so much.