First of all, join the club! It's happened to many of us unfortunately.
Secondly, after reaching out to them decide if you'll leave negative feedback if you were stiffed. You can place the transaction into Problem or Unfinished status.
If you feel it necessary to out the member, do so as a warning to others who may be considering a trade with him/her.
Follow my blog - I Identify as a Card Collector.
“Aslan didn't tell Pole what would happen. He only told her what to do. That fellow will be the death of us once he's up, I shouldn't wonder. But that doesn't let us off following the signs.” - Puddleglum in The Silver Chair by C. S. Lewis