Soldato
Funnily enough, I knew a drugs kingpin once. The reason I knew him was through association with a girl friend (I should say acquaintance since I really wouldn't call her a friend) who failed to pay him for his "services" (being, no doubt, some drugs). Nice chap - he broke both her legs for not paying.
What did you expect him to do? If one person gets away with ripping him off, everyone else will try their luck.