Online Fraud Named Event Manager How I Can Take A Step Against??

Dear management ,
if someone is cheating on social site such as facebook, how can i take step against that person??
a guy from facebook said he has modelling opportunity for freshers. and forwarded details for shoot and sent me his own id proofs,stating that he is event manager and he charge for 15k for registration charges i did not paid him full amt as i had doubt on him.i transferred 5k on his given account number .aftr getting pymt he stopped conversation from his side and now not responding to calls n sms how can i get my money back.
i am not sure whether the details n id proofs he sent are original or fake.

Before paying some unknown person on FB ,what steps did you take to verify details?
Write to FB and try and find out IP address and further details or ask civil police to intervene.
But understand that your carelessness has cost you Rs5000.

I spoke to that person now he is ready to pay me back and asking for my account no.should i give him such details.even aftr knowing he is a cheat.