If your son is a registered student, the teacher is surely not right.
However, your son is not registered and the school has allowed for 3 free classes. The teacher has no responsibility to provide materials to your son.
It is pretty clear. Why it is not clear to you ?
Even if you are a tax payer, you can't barge into any public school without proper registration.
It is called "bully" when you try to take advantage of the Chinese school.
Defaming an individual and an organization is called libel. Libel is not equivalent to freedom of speech. You could be held responsible legally.
While you are mean, hope you are not ignorant either.