Contracted Employee Looking for Vacation pay from Former Employer

I am a contract employee working at a medium-sized company. My former employers had suffered severe financial difficulties, including filing Chapter 11 Bankruptcy. The client offered the chance, to myself and my associates, to switch employers and still work for them if we elected to do so.

My former employer stated that they were going to pay all of us our unused vacation pay i.e., days that were accrued, but not taken. However, before they would do so, they wanted the client to pay the unused days (remembering that we were contract employees). The client agreed and paid the invoices (detailing names and the fact that it was for vacation days), with the understanding that our former employer would then pay all of us. Our former employer has yet to pay anyone as promised.

What is the law regarding this situation? I should also point out that most of the employees are based in Pennsylvania, but some are in New Jersey. Our former employer is based in California.