I think you showed great restraint, something I don't think I would have done with such a bombardment of abuse. A formal letter to the secretary is a must and request you are informed of the outcome and any defence they think they can offer, not sure I'd want an apology off them, if their like that it wouldn't be a true one IMO and they'd be only offering it because they were told to. I bet you felt like a thorn between 2 (put your own word in)