The key to getting stuff like this done is for those that get ripped off to get in contact with the appropriate law enforcement agencies. It may take a couple of people getting ripped off to get them to investigate, but if that is the case, they have to actually have complaints with which to work.
I see too many instances (not just here) of people that decide that for $50-100 it isn't worth 15 minutes of time writing a letter or telephoning law enforcement, and it is that inaction that contributes to allowing the pond scum to continue to rip other people off.
If you get ripped off, take the steps to help excise that festering boil on the buttocks of the world...