Now, im being black-mailed for more money, being told that my money would be returned only if I sent more money.
They will keep telling you that until they run you dry . . . this is no money coming your way.
Im in still in touch with the scammer,who doesn't know that I have seen through their fruad. I have promised them to send more money in the next 10-15 days, in a hope to get them nailed.
Is there anything I should do ?
This can be dangerous. They are in another country, so there is no chance that any of the information that you have will really help to "get" them. I would break off contact with them. If they hreaten you, tell them that you turned all of their information over to the FBI and Secret Service.