Has anyone considered opening a criminal case against such people? Evidence of fraud shouldn't be too hard to collect.
My observation given the vast amount of financial fraud occurring everywhere (with a paper trail), fraud is one of those things that's only selectively prosecuted when you piss off someone powerful enough or with the right connections.
Even if we assume fraud actually starts being prosecuted seriously, I'd assume the astronomical quantity of financial fraud out there would take priority over a relatively little amount of employment/candidate fraud.
Also, wage theft isn't fraud exactly.