In the early days of eBay for me, circa 1999/2000, a guy in Canberra hadn't sent something I'd purchased from him (using an at-counter bank transfer) and eBay wasn't helping, so I contacted the AFP who were also the regular Police for people living in Canberra. That got things moving pretty quickly when I just sent the seller and eBay the name of the AFP officer and the reference number.