DaasYochid
All I know about superme is what she posts on this forum, but I have the impression she is in a complicated situation. This 50$ episode has to be understood in a context of difficult relationships with other students, with teachers, with her parents. She needs IMHO to talk a Rabbi who not only can pasken about 50$ after hearing the relevant facts in regards to this episode, but who can also simultaneously have her trust, be detached enough she feels safe she can tell him the whole story (and who knows how many other stories she would like to tell) without others hearing about how she talked to Rabbi XYZ etc etc, and yet be somehow in touch with the school, someone in a position to improve relationships and whom everyone respects. There is much more at stake than 50$.
Superme
Be Hatzlacha and please let us know the teshuva when you get one