Personally, I would quit teaching them. I don't see the point in keeping them as a student. I suppose you could try to fix them and correct their behavior if you have the time and inclination, but how do you instill a set of morals that is lacking? How do you get someone to accept honest failure as a better outcome than cheating success?
If you have lots of students, is the time and effort involved in helping this one student going to detract from helping the ones who are actually trying to learn? Especially if you fail to get them on the right path? If you consider it your responsibility to help them, and not leave them a victim of their own free will, do you have the extra time so that your actions do not cause harm to others? By that I mean, neglecting your real students, and missing the opportunity to help them advance. Will the good done for this errant student balance out the bad for the others?
Did you mean two hundred words maximum, or two hundred words exactly? Do contractions count?
