please always make sure you check (scout) people you are buying before bidding.
If a deal looks too good to be true, it often is..
there's been a few cases in the past of dishonesty in the Ads section. Unfortunately whilst this isn't a particularly nice way to behave it has been ruled not to be in breach of any rules. As such, there is little fallback should you be duped in this way.
Also, please avoid naming and shaming in the public forum on the chance that it was just a case of honst mistake.