You must be pretty stupid to purchase an online account without informing yourself about it.
Please look up these rules for a LoL-account:
1. Try to get the email. Yes the whole email. Not just the information. I could tell you the reg. email is:

and its simply not true.
2. Try to buy from ubertrusted. Means with 120+ TBM and/or from admins and/or trusted seller.
3. Try to pay via paypal. If your trading-partner hasn't got a big knowledge then try to let him send a request per paypal. Its almost not possible to get a refund for virtual goods through paypal if you sent by yourself.(You need the police for it)
So you can catch a potential short-term scammer.
4. Try to get a seller from your country.
5. If possble, level yourself.
For the previous scamms just simply go to the police. Doesn't matter how much you lost.
We can't help you here if its not e*gold.