Illegally subletting a room in an apartment....?

Wildcat is right, verbal month to month is legal. Any ways, nothing will come of your situation. If you go to joe and ask for your money you wont get it, he will say mary has it. Marys the one who gave you the rent receipt right! Just like you said in your additional details, "she illegally subletted a room to me" Consider the whole thing a wash and move on.