me and my friends have grinded it out on primas sites, nordicbet, purple lounge etc and believe me, they won't change your nickname.
tried to catch an e-mail adress out of microgaming, but they sure as hell don't seem to have one, atleast on here,
http://www.microgaming.com/pnpokerroom.php, if that was the site you we're looking for.
if you haven't played for real money on bet365 u might wanna try if they can help you. obviously this is the reason why everybody's nicknames are so damn ugly at prima, it's such a old network :-)