It seems some people don't really respond until the pain is real for them. Unfortunately, this is often when they are being dropped from a class, or worse, the school. In my experience, these are students who are accustomed to failure and their demeanor is part of their defenses.
One approach with these people is to confront them very directly, followed by aggressive disciplinary action that gets their attention.
Another approach is to challenge them to self-advise - to come up with solutions rather being told what to do.
