Legal Question in Business Law in Florida

The key question here, which is not clear, is whether at this point the gym was unjustly enriched or not? Meaning, did you owe them the money they charged or not? If not, then you should file a claim in the small claims court against them. If they were owed the money, then what is the problem? If you think that they violated the law in some way here by the way they handled it, which is possible but not at all clear, then you should discuss it over with law enforcement either local PD or contact the attorney general or county prosecutor.