Skip,
I have been in the exact position you are in. Let me tell you how I handled it and you could/may learn from my mistakes.
I relocated to northern California several years ago to help out a "friend". Don't get me wrong, I was in a dead end job and wanted a change, so there was something in it for me too...
Things were not what they were portrayed to be, in fact not even close. I humbled up and went to talk to my friend mono e mono...First mistake. Should have called to have a meeting with the entire management staff...Why? Well my "friend" just told me exactly what I needed to hear, for the second time.

So the next time I went and talked to him I had a written list of demands, all of which had been previously discussed in other "meetings". Mistake number two. Again, should have met with the entire management staff, or at least had one other person from the company there...Same same.

So the last time I went to talk, which was about a week later, I was extremely pissed off and vented to the management staff and the boss at the same time and guess what? None of the previous discussions ever came up, like they never happened, so I was portrayed as the "Hot headed whack job" by my "friend"...

So I packed my shit, calmly explained that I hoped his business venture turned into what he put into it (nothing) and left. I still feel like I was seen as a whiny little spoiled bitch and that really torques me the wrong way...Not that it matters because the business did fail an abrupt painful death, but I hate losing.

My only advice I am qualified to give out at this time would be to meet with the direct person who gave false promises and call him/her out in front of his/her peers. Stay calm, don't raise your voice and have a "script" if you will, of what your expectations are and a time line to get you to that point (very important, set a the next meeting while your there). and don't be afraid to "humble up" if it comes back on you....Sometimes expectations go both ways....

If all else fails, wash your hands of it...Life is too damn short to either work in a hostile environment or be unhappy for settling for "less" than what you deserve.
Wish there was something I could do bud...Good luck.
GT