Teacher confiscated my ruler, what should I do?

I say speak you mind and tell the coordinator that it was wrong for her to do that. For one how can she not tell that this is your possession unless she is a complete and utter incompetent buffoon. Second why would she then give it to the art department if you had it the smart thing would of been to keep it in her desk chances are she thought it was cool and now has possession of it. Finally she has no right to say its your fault for not telling her when she should of already guessed that it was yours in the first place. I say make them pay for a new one and to what kind of sentimental value did it have just saying because that will help with the story.