Read Thread: cell phone policies
SWMBO is retired now, but where she taught the rules worked this way: If caught with a cell phone or if your cell phone made any noise and interrupted class, the teacher confiscated it. And the student didn't get it back. It was turned over to administration, and the only way they'd part with it is if a parent came in to claim it. You'd be amazed at how many phones they had left at the end of the school year.
Do I detect a note of sarcasm in your use of the words "service animal"?