Realistically the best option. We're talking shit ITT about the mafia and waiting outside to teach him a lesson, but roughing him up probably isn't the best idea. I know TPB has some Cousin Eddie's out there.
I will almost GUARANTEE that if you get the right attorney you could crush his soul. Hard lesson to learn at a young age, but when you're a liar and cheater, it almost always bites you when you're as smug as he is.