Dear Dennis,
There is an organization that, in theory, would be responsive to claims of mistreatment of Foreign Experts in China.
That would be the national
State Administration of Foreign Experts.
I personally have emailed them a few times. I have never received a reply. Likewise, I have read of several similar attempts to contact them, all with similar results.
Some wag on another forum once described SAFEA as "a toothless, sleeping watchdog." I have yet to encounter evidence that contradicts that description.
There are other agencies that,
in theory, might assist you. You might try your local SAFEA office, if there is one. You could try the local education bureau, or even the PSB. You could even hire a lawyer.
However, in my experience, you could hire a mime troupe and get equal or better results than employing any of the above.
The bitter truth is, if you are in an employment jam in China, don't expect anybody to help you. Not your embassy, not anybody.
The sooner you are free from the notion that someone is going to make things right, the sooner you can focus on solving your own problems on your own terms with the resources you have available.
Your best tool in any situation in China is, believe it or not, negotiation.
If you have specifics about your situation that you would like to share and ask for guidance on, I'll be happy to respond.
But, right now, I'd dismiss any idea that any agency is going to assist you. It does happen once in a blue moon, but, some people win the lottery too. Don't count on winning the lottery.
I wish you well.