I'm with Henchman... It Happened to me. I spent nine months trying to get paid and would receive tiny payments and lies about payment schedules. I called lawyers and tried to file with the labor union. But, it is really tricky... the employment terms as an independent contractor, vs permanent employee.
Anyway, nothing was working. I was texting the exec producer/director every day. It was horrible. Finally, I made an exhausted post on Facebook, just warning fellow mixers not to take jobs from the production company. It turns out he scammed a bunch of people. Word got out quickly, I guess, because within 24 hours I got a call saying the balance would be wired to me immediately, if I took his name off Facebook.
I was paid, and deleted my post. It was a shocking, and pretty disheartening experience.