he gave u a csgo key so i dont see a reason to report any one and also calling out is against the rules

Dat english.

What did you expect? A game key? Before trading, you should've learned a bit about it.

DId you use that CSGO key? because you just posted the code for everyone to see

1. Calling out is against the rules of this forum. Please read the FAQ (link at the top of the site)
2. It looks like an origin key, not steam key

First of all, calling out is against the rules (so remove the pictures from here or else the mods will suspend your account). Secondly, report him on steam support, steamrep (although I think they don't accept reports for fake keys - someone give me info about that), and -rep him on steamgifts. Use all these photos and explain the situation, in order to report him. Also, never trust people that randomly add you.

And what is his steamgifts rep? I'm assuming he doesnt have 1.
Your greed lead you to this outcome. Take this as a lesson and be more level headed next time.
As mentioned above there is nothing the support can do to help and calling out is against the rules (which will get you suspended), best remove the pictures and take it fiasco as a lesson.

Es para que aprendas. Siempre que vayas a cambiar un objeto de intercambio por un serial, pide el serial ANTES de la confirmación por móvil. Si el otro tipo se resiste, probablemente no sea buena idea hacer el intercambio.

Luckilly you lost only one key :)
I know people who lost their life savings in simillar way :/ Usually if offer is too good to be true... it's not true xD
Hope you learned your lesson :)
And fuck scammers. With a stick. In the eye.

Please don't use google translate. >_<.

CAN PEOPLE PLEASE STOP CREATING THREADS ABOUT GETTING SCAMMED?

ITS YOUR OWN FAULT FOR FUCK SAKE

If someone scammed you, report him to Valve and Steamrep with evidence. Do not create forum threads about it.