It all depends on what a 'Huge amount' of money is.Your best recourse is to file a legal claim in the country of the individual that owes you money (the USA). To do that you must engage the services of a local attorney. If that is less then the 'huge' amount then that is the way to go. But first find out if your former client actually has the resources to pay you if you are successful.If the money is less than $5000 and if you know someone in the USA who lives in the same area as your former client, you can assign the debt to your friend and he/she can sue in small claims.
Insurance Bad Faith Attorney