Declined 76561198064078004 - Scammer

Victim:
steamID: Fruit_Bomb
steamID32: STEAM_0:0:20944987
steamID64: http://steamcommunity.com/profiles/76561198002155702
customURL:
steamrepURL: http://steamrep.com/profiles/76561198002155702

Scammer:

steamID: Dev.<3
steamID32: STEAM_0:0:51906138
steamID64: http://steamcommunity.com/profiles/76561198064078004
customURL: http://steamcommunity.com/id/TAKATABRO
steamrepURL: http://steamrep.com/profiles/76561198064078004

Short description: Posted that i will trade TF2 stuff for dota 2 invite on playdota.com forums. then that guy added me on steam, told me that he is building a reputation and i have to trade with him 1st because my reputation is lower, i of course did that, and traded him all of my items for a dota 2 KEY with 2 invites, he gave me an already activated key... and went offline and I think blocked me.
Can I recover my items please? Hope this evil man gets banned...

Screens:
http://i50.tinypic.com/3462q2w.png
http://i48.tinypic.com/178wid.jpg
Sadly I don't have screenshot of chat log.

Screenshot of trade history in egnlish: http://i49.tinypic.com/esj1nr.jpg

LOL, CAN'T BELIEVE I WON DOTA 2 AT GAMERSBOOK GIVEAWAY!
But still , can you please recover items from this trade and punish that scammer?

Without a screenshot of the chat, there isn't much that can be done.