Catch-22 tax/salary/visa situation

:help:

I am currently in the process of applying for my ARC, and my employer is refusing to pay me any official salary until I have a bank account and ARC, and they also refuse to pay me cash in hand. I have been there since April 1st, and since then they have given me one cash advance from my salary, which was only a small part of it, so by now they owe me a fair amount. They gave me this along with a formal written acknowledgement that the advance would be deducted from my wage proper along with tax and medical insurance. My question is, how can they tax me on work done prior to receiving the ARC, and why are they making me pay for health insurance that I’m not yet even entitled to? They don’t seem to understand that until I get the ARC I’m working illegally, and that the tax laws mean squat until I am legal.

Does anyone know of any official stance on this, or where I can get more info / back-up?

Thanks in advance!