In reality, if you are in and educational setting or not, the answer is pretty much the same.
1) Document, document, document - document everything. Make sure who ever is the next step up on the management is in the loop. At some point, if this was professional, management might want to include the actor's agent.
2) Try to figure out what is really going on here - lateness, in my opinion, is more about not making the show a priority - I mean, other actors can get there on time. It's a long, hard path to make an actor make a show a priority. This is a huge part of managing creative people - and one of the big challenges of being a younger stage manager without years of experience and tricks. Ultimately you need to figure out who, within your management style, you can get better behavior out the actor. And, you may just get a little improvement - some people are just jerks (and in this business, we have a lot of jerks.)
3) Never give up on making it a better environment for everyone. I know that I have been in situations where the show has been hi-jacked by one actor, and the producers sort of turned their back and left me to hang . . . I tried in small ways to better thier behavior, and nothing. But, what I did do, was it make it better for people who had to work this actor.
Good luck.