Irena, I think you need to consider carefully what you want to accomplish before sounding off.
As far as I know, no teacher has ever thought of himself or herself as a bad, mean, or unskilled teacher. Nor do I think you can reform the ignorant or biased ones by merely pointing out how your child has suffered in their class. They will still blame your child; plus they will find you vindictive and pushy, and they will think you overestimate your child. This will aggravate you, and yet nothing much is likely to improve as a result.
Is your DS still going to be at that school next year? My focus would be trying to make sure that the bad teacher doesn't pick your child's teacher or poison that relationship ahead of time. I do think you should have a frank talk with the principal, and cite for him/her chapter and verse of the law that protects children with disabilities. It's OK to specify to the principal how bad it's been, and to request a teacher with specific traits. Fairness, understanding of disabilities, there's a list you can make here that will be positively useful.
Year's almost over! Hang in there!
