I don't really know, I haven't used my account in over a year probably.
Anyway, I guess signed message from an address posted in a unedited post , posted over an year before is what the admins want. Send them an email/PM , link either the post I showed or the archive link(to verify the unedited claim, in case the hacker edits it). You should get back your account in 1-2 weeks , best case scenario, admins are busy.