How do know what to look for to know what is real and what is a scam. There are a lot of sites the say they will cast it for you but I know some are scams. I have tried spells myself before but they didn't work.
For one I suggest you don't trust people to cast spells for you, especially if they are asking for money or payment of some kind, also you shouldn't always cast spells with your own intent not the intent of others.
If you are new to magick don't get other people to cast spells for you, learn from the beginning and cast spells for yourself. Start by learning the basics in magick, what it really is, and what it isn't. I believe that you should have first hand experience with the magick, this is because no one will ever be able to cast with your intent.
In general,its bad to get a spell cast for you via the internet.
As for the spells that didnt work for you,that can happen for a number of reasons.From the looks of it,you're a beginner.Spells take time.Not only in casting them,but in learning how they work;which is the key to them working at all!