I was confronted with this bull twenty plus years ago. homeschooling or private school was not an option.
My actions
We all can make a difference one person at a time. And I encourage you to do the same.
NEVER be confrontational. Always be calm when confronting the teachers and administrators. They stop listening and you get branded a crazy forever.
Monitor and review your childrens school work weekly. Never raise your voice or hit your head on the wall. The kids do not understand and it only scares them.
Never talk above their head but always talk to them on their level of understanding
Arm yourself with knowledge regarding the subject matter they are teaching. Learn how THEIR system works. Not the way you think it should work. (remember . . . do not hit your head on the wall. It only hurts you and hard to explain to the neighbors)
Slowly but surely begin objecting to the study material and teaching material in a sane and reasonable manner. Offer solutions . . . calmly
You will NOT see results for a long time.
Many many years later I can look back and smile and say to myself, a difference was made.
one person at a time, one word at a time and shall i dare say in the spirit of love of the Christian doctrine
Speaking softly, learning how their system works, etc etc... Your child does not have time to wait for this to work. GET THEM OUT.