I worked for a restaurant that did this to me. To make sure I hit the "minimum hours" (when you start talking about hours vs tasks or responsibilities you probably aren't getting into a legitimate salary arrangement) they would have me clock in and out, and I'd get pay stubs with 40 hours (less if I worked less) and the overtime hours paid at $0. They withheld my last paycheck when I quit and stopped responding to my…
As a small government advocate, i have no issue with labor boards. the alternative is violence or unionization, neither of which are optimal in resolving disputes like these in a civilized and efficient manner.
[1] https://www.nber.org/system/files/working_papers/w10481/w104...