Make the kid think Santa brings you gifts on Christmas too; not just children. THEN, what you do is, you have "Santa" leave crappy gifts for them (also maybe a shitty note, but that's entirely up to you). But you...YOU get awesome gifts from Santa. Prance around with them all proud of your accomplishment of being good all year.
Then you can be all, "Wow, I guess you really blew it. You should listen to me more, and maybe next year you'll get better stuff." And throw it in their face whenever they act like a jerk.
I'm pretty sure this will pay off in the long run.
:toke















