1)If you want to volunteer, do it as you please. Don't say doing it to change people's ill impression because "OTHER" Chinese do not like volunteering or "donating". It's like "acting" to be a saint. I found it rather insulting and pretentious. If chinese do NOT participate the volunteer work much, it's not about the ethnics or selfishness, it has lot to do with the economical standing, the language skill, and the personality--being shy and introvert.
2)If you feel hurt by the "director"'s response, confront her/him and fight. It's likely you don't have a big social networking, otherwise a letter with such language won't be drafted by the director at the first place. Even if you made an overstatement or improper accusation, the educator has no call to react like that. Can't feel much respect or regard from that "kick-out" letter except a haughty attitude and irritation. What you are posting is also like "hiding" here and smearing their reputation without the guts to even name the school, the director, and the instructor. If what you said is "untainted" , what are you worrying about by naming them? Is that illegal? Why don't you share this story with a local paper columnist and let some guy write a glorifying story about the school? No matter how delayed a complaint is, a professional and responsible person will do an investigation and try to ease the tension. If what you show here is true, it is quite obvious the school director got cornered by your "serious" words and try to bite you first to secure her position. It IS a serious accusation. The discrimination might be true but few people have the courage or honesty to admit it. If I were at your position that a parent felt troubled by the school's response, I would get everying in the light and try get an apology. Somebody has to take the position to regret. Either you or the person who insulted you or your daughter.
3)Poor verbal skill is not a problem. Agitated minds ARE.
4)Your complaint letter is more like a burst. It's like Ren Wu Ke Ren, Wu Xu Zai Ren. It's also somewhat like stabbing people's back. It's a bad asian heritage---hold-nag-hold-brew-hold-hold-hold-burst out of blue. If you kept silent at the beginning and never brought that issue up but you can't truly tolerate it, recreate a similar scenario with the very same person and then complain two things together and voice your concern. Always communicate with the primary party first and do things in an open platform. Be consistent and be truthful and again consistent. You smiled at them, do it always even if you never liked them. Or, You don't like them, don't ever offer a sweet smile and say "I love you" and then turn around with a chilly storm.