It is not easy as your job really requires good customer service too. As teachers, we do need to deal with different parents. We really need to be tactful in our words to avoid further conflict even when we are faced with unreasonable request like the old man wanted additional medication while doctor is concerned of wound infection. Since he is single, you could have used your charm to ease his anger. Just a little joke! I can really understand your frustration very well!
Hahaha! I can relate, teachers have to deal with unreasonable request from some parents and naughty kids as well. It's not easy.