Watch out for this scam

So i was playing mm2 normally and a girl asked me if she can offer for my darkbringer and i said "sure" and than she overpaid for it and i asked her "are you sure?" Because i didn't wanna scam her and she said yes and we both accepted, the weapon didn't show up in my inventory but she still had the darkbringer and i asked her if i can have it back and she just called me an idiot and left so yea thats how i lost a godly :(