How do I report that my employers are illegally taking my tips?

I word at a sushi/hibachi restaurant that I strongly believe is in violation of federal labor laws. When I work in dining they take 30% of my tips and when I work in hibachi they take 50%.

This money does not go to bussers or bartenders, and we are expected to tip these people separately (although we only have bussers one night a week, so no big). I am told that the "Share Tips" as they call them go to the house, and was told this is used to pay the chefs and managers.

I can't find any direct Missouri law against this, but I have seen several things on the DoL's website that makes me feel this is illegal, even though I've been told that this is customary for Japanese restaurants. I've also heard that people have to comply to the most stringent law, whether it happens to be Federal or State.

Here is the main source of information I'm using:

PDF on Tips from the DoL (pay attention to Tip Retention and Tip Pooling: http://www.dol.gov/esa/whd/regs/compliance/whdfs15...

So I think I have determined this is illegal. I just can't find out how to report compliance issues in Missouri.

1) Should I try to report it to Missouri or Federal DoL?

2) How do I report?

3) Can I do it anonymously so I don't lose my job?

4) Is this going to be expensive?

Because I'm just a poor college student, guys. I can't fund some lawsuit that will probably amount only to a few thousand bucks. Thank you for reading this long mess.