If it's a single scammer, find out some personal details and use that to mess with them. Eg: "How was your birthday on [insert their date of birth here]? How's your sister, [insert sister name here]? I heard she just finished studying [insert qualifications here]. etc." Gimme mah moniez back.
Otherwise, if I can't do much about it, I'd sit in the corner and cri.
"Holding anger is a poison. It eats you from inside. We think that hating is a weapon that attacks the person who harmed us. But hatred is a curved blade. And the harms we do, we do to ourselves."-Mitch Albom