What are the grounds of verbal abuse of teachers on their students?

Just wanna know my rights as a parent kasi po ung anak ko na nasa grade 2 nagsabi sakin na natatakot daw siya sa teacher nya. His teacher told his students (including my 7 year old kid) na pag may nakita daw siyang kalat at ipapakain daw nya sa mga estudyante nya and pag mabagal daw sila magsulat ay pipingutin daw po nya yung mga bata sa tenga. Nag request ako sa head nila na ilipat ng room but what i feel is that they are defending their that teacher telling us that he was just joking the time he said it. Hindi namin nakausap yung adviser teacher mismo dahil time daw po ng klase. Now iba na po adviser teacher nya pero un pa din po teacher ng anak ko sa math subject. I asked my son kung ano sinabi ng teacher nya nung lumipat siya ng room, the teacher said " maigi at mabawasan estudyante nya.

write a letter or talk to the principal