Break his legs. Seemed to work for me.
A bar owner owed me ?1000 back in 1996. I worked for two months and genuinly thought the guy would pay( he was obviously a bad planner as he had major money problems) I was living on my credit card so no worries about cash so I belived his lies. Eventually debt collectors came in as the guy owed money to other people. As the heavies were in I helped the guy move a large wardrope although about 10 minutes before we had been having a heated debate. Anyway I tripped up and to get my balance I pushed my hands forward forcing him off his feet, he fell awkwardly and the wardrope landed on his legs broke both ankles. The guy thought I did it delibratl,y became really scared and paid me a few days later. I got more money than the debt colectors and it realy was all an accident.
I sugest you just take goods to the value of the debt from his premisis as if he was employing you illegally then he cant really report it can he.
Maybe I am wrong but eh! its worth a go.