Is the employer allowed to hold your wages when you quit?

I worked for this company 4 months I received a email attacking my hair and personal look. So I quit on October 3rd after receiving email. I was due my paycheck on Oct 15th which is normally deposited automatically. For commissions and days worked. I did not receive my money. So I sent an email asking the owner where my money is he said before he releases my funds he wants a resignation letter. I would like to know my legal rights before replying to his email