My employer does not want to honor my hourly rate

Hi,
I am a consultant and work for a contract house, I get paid hourly for my work. During my first year working for my employer, they deducted $Y every hour worked. The deduction was due to the fact that I am working away from home and that deduction served as a non-taxable income for the first year which was used for my meals and lodging(Perdiem).

At the end of the first year of employment, instead of paying me the hourly rate, that was originally agreed upon, he continued paying my the same amount, but this time I was not getting any money tax free for my meals and lodging.

For Example: My hourly rate : $50
for the first year, out of $50, $15 was non-taxed.
So I was getting taxed for $35.
At the end of first year, instead of reverting my pay back to $50 and me paying on taxes for the entire amount, he now says that my hourly rate is $35, and he did me a favor by giving the $15 tax free for the first year.

This has been going on for 9 months now and now he says, if I want to quit I can quit, but he will not pay me a single penny.

I need legal advice regarding this issue. What are my options here?

Thanks in advance,
JG