"we had a LONG discussion PRIOR to the school year starting that under NO circumstaces were they to ever fight back. PERIOD end of discussion"

Congratulations - you have failed as a parent.

Under NO circumstances!? So if your child is getting jumped in a bathroom in the middle of a class period when there aren't other students walking around who could help, he/she is just supposed to curl in a ball on the floor and keep on getting hit?

I feel sorry for your child/children.