When someone owes me a good amout of money I show up at their front door when I know their not home but when their wife and or other members of their family is home to let them know that I know where they are and that I haven't forgotten about the money that they owe me and I keep records of everything, you spend 21 years in the bizz and you become this non-trusting machine to everyone in the bizz,you have to learn to put the scare in them to, show up at their house with a few of the guys that got ripped off and they'll think twice about ripping off the next tech plus it gives you witnesses if anything goes wrong or violent.
I'm not promoting violence upon someone's family (I would never suggest that) I have a family of my own but you gotta stay in the back of these people's heads and send a message that they screwed over the wrong group of guy(s).