i got scared by fire sap

theres some way i can take the item back? i send a proceed and charge all the proof but steam tell me nothing could be done... i hope steam rep will ban him

?? I have no idea what you are talking about.

If your items are in the Valve Escrow, you can cancel the trade, and get your items back.
If you where scammed with out-of steam trading, then no.
If it was only in-steam game items being exchanged, and something was wrong, make a Steam Support ticket: https://support.steampowered.com/

You can report a scammer here as well: http://forums.steamrep.com/forms/scam-report.2/respond
Provide screenshots of:
- Chat(s) between you and scammer
- Trade history / Trade offer history of the items been exchanged between you and the scammer.
- Paypal / skrill / whatever online payment system you where using.