Contact the staff, explaining your situation (in detail and include links):
http://support.chess.com/Tickets/Submit
(Select a department, hit "Next", fill in the form)
I imagine that they'll help you reset your password, and close the GoBlackburn account.
I recently joined, but I see now I have an old account (from 2011) that I never used. I would like to change my user name that that old user name, but I can't because it's taken...by me. Password reset process fails because both accounts have same email. Any suggestions how I can kill that old account and release that old user name?