Wis. Stat. § 104.12: Complaints.

Any person may register with the department a complaint that the wages paid to an employee for whom a minimum wage has been established under s. 104.035 are less than that minimum wage, and the department shall investigate the matter and take all proceedings necessary to enforce the payment of that minimum wage. Section 111.322 (2m) applies to discharge and other discriminatory acts arising in connection with any proceeding under this section.