Trade error

[Faaborg Cykeltaxi bandit.gg]

Hello,
I recently lost about 800$ in CSGO skins to a trade error, i sent my friend a trade offer and quickly declined it after (on purpose)
But when I clicked "decline offer", it said "Failed to decline (error 15)" or something like that. I then clicked OK and it showed my trade had been accepted by some random guy who's not my friend? I had apparently sent the trade to someone else while it said "Failed to decline (error 15)". So I lost 800$ in skins, to a Steam error. Can I get a refund?

This guy is not my friend! And it sent all my skins to him.

https://steamcommunity.com/profiles/76561199046849505

[wuddih]

your account is compromised, likely phishing aka you logged in on a fake Steam login website.

please do the following steps in order to secure your account:

1. Scan for malware (with whatever)
   
2. Deauthorize all other devices
   
   • https://store.steampowered.com/twofactor/manage
3. Generate new backup codes
   
   • https://store.steampowered.com/twofactor/manage
4. Change your Steam account password, preferably from a known safe device.
   
5. Revoke API key (revoke button there? click it and confirm)
   
   • https://steamcommunity.com/dev/apikey

nothing will be "refunded"
https://help.steampowered.com/en/faqs/view/3B6E-B322-2400-8D24

[DC-GS]

You can't decline an offer you sent, only offers from others. You only can cancel them or verify in Steam Guard.
Are you using Steam Guard App?

Like wuddih said, most likely you gave your login data away and have an api key planted.

Also public naming/shaming is against the rules.