Public shaming for scamming you out of x-hundred dollars. If he keeps it, publicly label him a scammer. He made you trust him to gift him something valuable. That's the same tactic used by phone scammers. "Skyler is a scammer", he scammed you. Yes, you were naive, but so are all scamming victims. Sometimes we are vulnerable and guillable and stupid. Please don't victim blame yourself or let others do that to you.