If you can link the impersonator to a profile here, you can report them through the report button on their profile. Make sure to include some proof so we can investigate further.
You can also report them in the offsite scammers section found here:
https://www.epicnpc.com/forums/off-site-scammers.30/
Always keep your wits about you. Always request a PM from them here on the forums. If they are not who they say they are, the ruse will quickly crumble!