Get together all the documents and go through the clauses. If it seems your right has been violated then have a lawyer write a letter to the apt mgmt with reference to those documents. A recommended lawyer by someone you know might charge 50-100 bucks. Since the disputed amount is so little the apt mgmt might accept your original offer.

Claims court seems like a good idea too but I have no experience of its intricacies. At the same time I see you indicate that it is not just about money but about tenant rights too. Way to go!

Good luck

-hydE