You can call the Wage and Hour division of the U.S. Department of Labor. If you want to take a less aggressive tack, you might call the labor affairs office of the Catholic diocese. I'm sure the institution is legally independent of the diocese, but the diocese can certainly put pressure on them. Most Catholic dioceses have an office staffed by fairly staunch labor rights advocates, since advocating the rights of labor is part of Catholic Social Justice Teaching - but if they don't know about a problem, they can't do anything about it.
Most Catholic institutions that are not specifically religious in their work, are now run by lay boards of directors, and those boards are often dominated by aging male businessmen who understand nothing but profit and smoking cigars. They need to be reminded at times.

-Joe-