Your employer is truly a work of art. Still, you can do a few things. I'd get myself a good lawyer no matter what. Preferably one that also practices employee rights cases.
Also, if I understand it correctly, money was deducted from your paycheck, but you haven't seen any proof that it was actually used for filing I 140. You have a right to request such a proof, just like any other thing you pay for.
Another thing, you should file for EAD and AP. Especially since your H1B is nearing its limit. It makes perfect sense and you'd want to have that for several reasons, like traveling (you don't really need to travel, just tell your employer that you plan to do that). It'll give you something tangible to hold in your hand (as both documents belong to you) within weeks from applying.
One last thing you can do regarding your employer (except for using violence, which might not be a very good idea, as tempting as it sounds), is telling him that you're looking to buy some property, and mortgage brokers everywhere are demanding some proof that you are indeed in the process of becoming a permanent resident (again, you don't actually need to see a broker, just let your employer think that you're doing it).
that's all I can think of at the moment. Anyway, I'm really sorry you're going through this. Getting a GC is stressful enough as it is, without the added joy of dealing with employers such as yours. Hopefully, becoming more proactive about your rights will bring some quick results.
Good luck.
