If he did get busted, then you got off cheap by just losing some money. Hey, care to trade positions with him?

It's even in the Emily Post Book of Etiquette: "If someone offers to go buy drugs for you and gets busted, you lose your original money. It is proper etiquette, however, to request a refund after you go down and bail his ass out."

If he was just ripping you off, then kidnap his dog and hold it for ransome.