Take screen shots of it all and then shut it down immediately. Draft a formal email outlining the issues and send it to the principle making clear that you expect 'them' to adequately address these issues to your satisfaction, or you will be taking it further with the board of education. I would also be making clear that your child is NOT to be in this teachers class until and if these issues are resolved. Make sure you keep copies of the screenshots and the email to send through to the board of education if the principle still fobs you off.