If you sent the money via Green Dot or similar, untraceable means, it is gone.
The scammers are probably in India or Pakistan, enjoying your money.
Here are two pages of links to (mostly government) sites in Canada and the USA were you can report those scams, or learn more about them.
Look here first:
http://800notes.com/arts/I2neMkbUAAo/where-to-report-phone-crime
If the reporting site you wanted is not in the above list, try this one:
http://phonehelp.2truth.com/complaint_sites_rev.html