I am a Canadian living in the USA. When I get buyers trying to jerk me in Canada, I do what every good Canuck does, I call the RCMP.

They actually enjoy busting eBay crooks, and they sometimes cannot believe that a Canadian living abroad would take such recourse. If they are slow, they will often oblige.

7 years ago, I actually found one kid's parents, and they welcomed the RCMP to lecture to their child before he made extortion a career.