What should I do about company violating labor laws?

I need to know what I should do about this company I work for. It's an LLC, and it has 4 employees. One of which is the owner. And lately things have been getting out of hand for what they're doing to us. Basically me and another guy (referred to hereafter as 'us' or 'our') do a lot of the work.They are taking money out of our paychecks for returning a rental car late, (the truck in their name, and after never instructing us to return it...which I have checked and is illegal) and have been giving us day rates without incorporating those hours into overtime hours (which we just stumbled upon and found out is also illegal). What should we do? Is there anyway to get someone involved to check the company so they stop ripping us off?