If you've been scammed by this user, then report it properly using this form :
https://bitcointalk.org/index.php?topic=260073.0From that, a trusted member willo tag him red so everyone knows he has a scam record.
You can also make a review in his "trust" section.
And remember that it's very dangerous to trade with someone who has a locked and/or self-moderated thread here, it means that he is most probably a scammer who doesn't want his victims to write in his thread.