I have to say, I agree with the last post. I feel for the OP (I've known people who have been duped in similar ways) and I'm glad it was only a small amount of money, but I don't think there'd be much of a case. It's not dissimilar to the idea of predatory lending - the idea of caveat emptor ('buyer beware') appears to have been significantly damaged by the knee-jerk instinct of people to trust, and demand, that any possible issue with a transaction has been regulated out of existence.
Back home all I needed to do was smile and say 'no thanks' to the odd person on the street selling raffle tickets/collecting for charity/handing out flyers, and more often than not they'd say 'no worries' with a smile and we'd go our separate ways. Otherwise they'd turn to the next person, either way it ended there.
In Hong Kong, I have to physically push my way through the rude SOB's who jump in front of me and scream about whatever it is they're selling, and continue to do so after I've registered my distinct disapproval. It is beyond infuriating - I hate the person that I have to become to walk down the street. Whether it's the Save the Children creeps, real estate agents on weekends or prols handing out free newspapers, none of them have any empathy for the people around them.
If somebody tried to scam me the way the OP was, at this point I think I would physically assault them.
Apologies for the rant