I'm not a lawyer so this is not actual legal advice, but rather my personal insight.
"Fanone" is not the same as "Fan1". So, no, you likely will not be able to retrieve the name. Also, I believe your copyright had to have been in effect prior to their registering of the name 'Fan1' for you to even have a chance at obtaining the name. It's a longshot but I doubt you'll get anywhere.