Despite what many people think it is almost impossible to employ pilots as contractors unless they are providing their own aircraft. Seriously I've heard every excuse under the sun for an employer thinking they have the right to not pay someone under the award. Is it legal... no. Just because a worker ticks 8 out of the 20 boxes of the employee/ contractor test does not make him a contractor.
99% of pilots will complain to their peers and other work colleagues on a daily basis about how much they are getting shafted. Yet all they need to do it make a complaint to the fair work ombudsman (you can remain anonymous). However only 1% of pilots actually have the balls to do this. So result, employer xyz thinks great, I can get away with it, even if I get busted for one pilot I'm still creaming it.
I know of a number of employers in general aviation that are making over 100K per year by just not paying superannuation. Pretty good little scam when you think about it.
You can still make a complaint after you leave xyz and get back payment for all money owed.