Like I have stated in previous posts, don't do work with out of state contractors. We call them mall-rats.
They travel all over, get local subs to do the jobs, the jobs are finished before a pay cycle, they are gone in a cloud of smoke, and you are left holding the bag.
Oldest trick in the book.
I'm sure the GC signed a waiver stating all of his bills were paid. If so, that is fraud. But like most mall-rats, they are paying for past jobs with your money, and any legal action will just drive them into bankruptcy.
Move on and write it off