Thanks for the replies.
Moving to the other town isn't really an option, it is a ski resort town and the house prices are about double what they are here.
I take DS to play at the daycare that backs onto the school and have seen first hand the school-yard violence and several of the mothers group ladies have changed their kids away from the school and are much happier. One of the mums was relief teaching there but gave it up because the teachers have no control or authority over the kids.
These are the only two schools in the area, the next closest are an hour away.

At this stage we are leaning towards selling up and shifting from the area.