I’m very sorry to hear this has happened to you. Scammers are everywhere, and there’s always been scammers/ frauds/ thieves, especially true with services from the web. It is really up to your own perspicacity to pick out the real lovely and truly extraordinary workers, from the thieves, they should not tarnish the work of these incredible women as a whole. They are in a completely different category of their own.
You can usually see patterns in scam ads: really low prices, terrible grammar, pictures that have been used before- it is up to your intelligence to discern these patterns. But heck, even the most discerning has been fooled, but that happens much less often if you know how to read the ads.