Boycotting Lelong is good but not enough to teach these unscrupulous sellers a lesson. You should have lodged a police report and send the police report to Lelong to have his account suspended or banned. If nothing else, this will only hurt him because he will have no oppurtunity to do trading in Lelong or the opportunity to cheat someone else. If you let it go like that (even for a small amount) these sellers will keep on cheating.