Improper Format I got scammed out of a Greedy Greevil lvl 1 unusual courier

Victim:
|steamID: here_soon
|steamID32: STEAM_0:0:42316092
|steamID64: http://steamcommunity.com/profiles/76561198044897912
|customURL: http://steamcommunity.com/id/here_soon
|steamrepURL: http://steamrep.com/profiles/76561198044897912

Scammer:
|steamID: DCK.tangina
|steamID32: STEAM_0:1:50564892
|steamID64: http://steamcommunity.com/profiles/76561198061395513
|customURL:
|steamrepURL: http://steamrep.com/profiles/76561198061395513

I've post on the Dota 2 chat of me looking for a Greedy Greevil lvl 3 unusual courier in exchange of keys. And then this guy (http://steamcommunity.com/profiles/76561198061395513) added me and offered the courier and we agreed in a 25 keys price.

I was so shocked to discover that it is only a lvl 1 unusual so I immediately PM him. He refuses to give the keys back insisting that it is a lvl 3 and even if it's only a lvl 1, he told me that a trade is a trade. I've attached a picture of our discussion, it is in Filipino so I've made a translation. You can verify the translation. I know I'm just stupid for not educating myself for the courier's naming structure but I really want this guy to get punished. The +rep comment he left at my profile is still present.

The approximate date and time of the trade is November 16 at around 8pm, Philippines (UST+8).

Somebody just mocked me out of this scam