Missouri not getting payed for work done please help

[PopsZ28]

I am a mechanic that recently switched job's. At my new job i am getting paid what he calls "contract Labor" on a percentage basis i get 20% of the repairs that i do. Now i have a problym with i just put an intake on a blazer just finished it this morning and went to test drive it all was good then my boss went to test drive it this afternoon and the motor started knocking. He is making me put a motor in it (he's paying for the parts) but he said i am not gonna get paid for the intake nor will i get paid for the engine swap my question is. What can i do about this as i am gonna be loosing about 5 days worth of pay right before christmas. PLEASE SOMEONE HELP

[Pattymd]

The law requires you be paid at least minimum wage for all hours worked. Contact the state Dept. of Labor. Problem is, however, you can not file a claim until (and unless) you actually receive your paycheck and a violation has occurred.