Compensatory Pay

First I would like to say I am not asking for myself, I am asking on the behalf of my Mom, Sister, Grandma, Cousin, and girlfriend. We all live in (Location: North Carolina) and all people mentioned before work at the same work place which is a Daycare that I won’t name for privacy reasons. They have to take classes in order to have credentials for their job which is teaching kids aging from newborn all the way to 5 years old. These classes are for things such as SIDS and CPR that are mandated by the state and the business itself. They do take place after work hours but the main concern is they are not getting paid for said classes. They brought it up to their boss/owner who for lack of better words got butt hurt (Saying things such as “All that I do for you girls”)- My sister, girlfriend and cousin get a discount for their kids. She said word for word that since it’s state mandatory she doesn’t have to pay them for their time but everything I have seen says they should be compensated. If they are indeed supposed to be compensated how are they to go about this.