I've spoken to our server admins and apparently only one person is capable of recovering/deleting accounts, and that's the owner of Pokémon Showdown. I believe his name is Zarel on the Showdown website if you wish to contact him (I've never actually seen him before so I can't be certain on that sorry!), but otherwise you'll just have to make a new account or remember your old password. Sorry we can't be of more assistance!