Dear [Mr/Mrs/Miss/Ms head teachers name], I am writing to inform you of the unfair treatment I received in my [class name] class due to a misunderstanding that occurred today.
I have done nothing wrong, as I had clearly explained to [Mr/Mrs/Miss/Ms teachers name] that I did not understand the task chosen for us.
As you may have heard, [class name] is not my best subject. I believe it is unfair that I was the one who was shouted at when multiple students did not understand the task, but the teacher only yelled at me because I was the only one who asked the teacher for assistance with the complex task set.
I passionately believe that any student should receive discipline if they have done something immoral or inappropriate. However, I also think any student should not face disciplinary action due to a misunderstanding or another student's mistake.
Considering my poor understanding of the task, I think it is significantly unfair that I must face punishment for not knowing.
I do hope you will reconsider your disciplinary measures, given that I believe that I have done nothing wrong.
sincerely
[your name and surname]
[year group]