Should something have been done about this?

When i was in 3rd cl in primary school i had an old teacher named Ms.McCarthy. One day as a joke me and my friend Kieran brought a fake spider to school and started scaring random clmates with it. Everyone thought it was hilarious except the teacher. She shouted ''PUT THAT IN YOUR BACKPACK RIGHT NOW'' Normally i wouldnt particularly care that she shouted at me but at the same time she punched me straight into the back of the neck. A bunch of my friends saw it and i knew it wasnt right for a teacher to do that so i decided i would tell my mother. She said she would talk to the teacher herself but the next day i told the principle myself. He listened to my story and after that called me down to his office everyday for 2 weeks for me to repeat my story over and over again. Eventually he stopped calling me down to his office and nothing more was said about it. The teacher got away with punching a student. Is it not illegal to do that? Should something have been done about it?