What a shockingly unprofessional thing for the school to do. I agree with ColinsMum that you should post the name of the school if you don't get a satisfactory explanation from them.
I don't think you said anything that was offensive. You just outlined the things that were frustrating to you. Hardly unreasonable on a forum such as this. If somebody from the school is using it too they would do better to take parents' concerns on board and do something constructive about them, rather than what they've done to you. Appalling.
