I'm afraid you are right, Fibilou. Her arrogance is astounding, and she clearly expected us all to tell her that she was absolutely within her rights to do what she did.
Still - I am sure she won't object at all when her children's education is disrupted by other parents coming into class whenever they want to, to get their children out.
And Princessparty - the teacher is TEACHING, not 'yapping on.' She is doing her job, as she is paid to do.
I am willing to bet that if she were to stop teaching early (thus depriving your children and all their classmates, but hey ho, that doesn't matter, does it?) so that they were all ready on the dot, for their parents to collect them, there would still be someone for whom this wasn't good enough, and who would want their precious child out earlier - so should the teacher stop teaching even earlier to accomodate them?
Of course she shouldn't. She is paid to educate your children, and she is fulfilling her side of the bargain. It is your role as a parent of a school child to support your child and to support the school and the teachers - something you are failing dismally to do if you are willing to disrupt their classes and to treat the teachers with so little respect. Teachers do a very difficult job - I doubt you could manage a class of thirty children for a day, let alone actually teach them anything!!
Speak to the teacher politely and respectfully about this situation, and you may get the result that you want.
If you carry on doing what you did this week, the headteacher will have to take action against you. She could even bann you from the premises.