Interesting contrast as time goes on.
I learned to fly 45 years ago when teachers threw blackboard erasers and no teacher, in school or in the cockpit, would have been sanctioned for shouting. Somehow we did all learn to fly. Some of us even developed a tolerance for shouting and sometimes we even recognised that it may have been appropriate.
Being rather old fashioned and having to maintain order with five teenage boys in the house I have occasionally raised my voice. (Well, maybe rather more than occasionally.) It may or may not be a result of their upbringing that, while some of my boys are a liitle dozier than others they all manage to pay attention when yelled at and discern the required action without getting flustered.
Once we took a friend of my daughter's on a sailing trip with us and as she had sailed with her parents and everyone else was busy I asked her to hold the course while I went and untangled the jib. Just about when I am hanging over the rail fighting three hundred square feet of sail she goes dramatically off course and I am knee deep in rushing water and hanging on for dear life. Of course I yell something like "Get the h*ll back on course" When I get back to the cockpit my daughter has taken charge an our guest has gone below because she was "upset." I am proud to say that I think my kids cope well in such situations.
I was 18 when I got my PPL and I probably would not have had the nouse to change instructors. In fact I had very good instructors and they did not shout anyway though there were the occasional sharp words.
That is all really beside the point though. You are a customer and you are buying the time. If it is in any way not what you want then change it without hesitation.
My eldest son is now learning to fly but he may not have so much choice. He is learning in the Canadian Air Force!