Formal letter

Dear Mr Scott,
My name is M. J. and I am Chritian's mother. I am writing in connection with a problem with my son. Now I explain the problem and I would like that we could make an appointment to discuss it.
My son has TDAH, and has issues with understanding and attention in class and the exams. Last week, one of his teachers, publicly compared in class, other exam marks with my son's. My son does not now want to go to class because of this.
Until now, we have not had a problem with the school. I would really appreciate it if you could arrange a meeting with you, this teacher, my son and myself. Thank you.
I look forward to hearing from you.
Yours sincerely
M. J

Very well written!

Formal Letter

Dear Mr Scott,
My name is M. J. , I am the mother of  Christian. I am writing about a problem my son has.  
My son has TDAH. He has trouble understanding and paying attention in class and on exams. Last week,  my son's teacher, compered (don't know what this word is) in class other exam (and I don't know what you want to say here) with my son´s exam. My son does not want to go to class because of problems  with his teacher.
Until now, we have not had a problem with his school. I would really appreciate if you could meet  with me.
I look forward to hearing from you.

Sincerely,
M. J