Dee
I'm very sorry for you.
But,as they want you to not be able to masturbate anymore,it is not surprising they were angry and want to increase the security of the belt...And to reduce your privacy(even if removing the door is a bit extreme).
However,@Laura is right.All lof us have tried it(and most of us still do it),but,as far as I know,no one get any success...The chastity belts are very secure,especially the ones from the main brands,their manufacturers seem to know very well how to prevent a woman to get any pleasure when she wears it.I agree with @Ines too about telling them to come discuss a bit with us,we could explain a bit about it to them,and it could make your situation a bit better.You may discus the possbility to take the thigh bands off during university,too.
Laura But you can always turn the light off
It allows way less privacy than having her door closed(even if not locked).