I know it's a common name. My wife is from Mexico, and my oldest stepson is named "Hey-sús". Same way the priest pronounces it in the Spanish Mass.Many pronounce it the same way we do. It's a fairly common name, south of the US.
I would have asked the teacher "is there anything you need to say to my son and my wife and I" and wouldn't have left until I got an apology. I'd also have told my son to tell us if he/she treats him the slightest bit different after that incident (and told the principal we'd be doing so).I ask the teacher if she has any questions. She says "who in their right mind would give their child a nickname instead of a real name." The Principal steps in again and tells us that all is well and he will have discussion with the teacher. From that time on Josh was very comfortable with his name and every teacher he had willingly used it properly.
Teachers today do more teaching kids what to think as opposed to how to think. Also, social engineering is the first course of the day always.
The only thing the kids are taught here is how to pass the state-mandated exams at the end of the year. No critical thinking required, just regurgitation of facts on multiple choice tests.
Unfortunately, of the six levels of the cognitive domain of Blooms Taxonomy (knowledge, comprehension, application, analysis, synthesis, and evaluation), most public educators don't move past the first level, knowledge, which is just recall of facts.
I ran into that issue a few times in my life. My first name is actually Bobby, not Robert (was named after my father who was Bobby Joe, I have a different middle name though).So, we go to the principal's office at 11AM to see what is going on. My son's teacher says that our son is being very disruptive in class. I asked "in what way?" She says that she calls him Joshua and that he continually states that is not his name. I asked what he says his name actually is. She says he says it is Josh. I tell her that his name is really Josh. She tells me that is ridiculous, Josh is a nickname for Joshua. I tell her that we have named our son Josh, not Joshua. She insists that his name is Joshua, not Josh. The Principal steps in and asks me if we can prove that his name is Josh and not Joshua. I tell him "you bet, would like to see his birth certificate?" He says that he would. I ask him to pull out the records that the school owns and take a look. He calls for them. The records, a copy of his birth certificate, his immunization records and our application for admission to the school all show his name to be Josh not Joshua. I ask the principal if he has any further questions. He smiles and says "not at all." I ask the teacher if she has any questions. She says "who in their right mind would give their child a nickname instead of a real name." The Principal steps in again and tells us that all is well and he will have discussion with the teacher.