Did you have a contract ? Do you have the agreement at least in writing somewhere (email etc?). How much are we talking about in terms of the amount ? You can f

Did you have a contract ? Do you have the agreement at least in writing somewhere (email etc?). How much are we talking about in terms of the amount ? You can find a litigation lawyer in NY state who can send them a "Threaten to sue" letter. The lawyer may charge you a few hundred bucks just to do this but depending on the amount, it may be worth a try.