So I'm getting screwed by a bookie. Ideas?

[Witzo]

Threaten to ruin his legit careers. Slander and Libel are only those things if they're lies. I'm sure you can rent a Billboard for a few days or even tip off the local news and get them a scoop. Of course these are all last straws as you're definitely not getting paid then :-/

Also if he's paying through poker sites you can threaten to report him to the poker site he's using. (At least FTP would since they love to randomly ban people and freeze assets)