No mention anywhere on how to cancel your account.
In this rather hypocritical piece they do, however, mention account suspension:
We’d suggest you mail them at [email protected], provide your username and registration email address, and politely ask them for account removal. Share your results!
Please note that AccountKiller.com is not associated with the business listed on this page. AccountKiller provides easy-to-understand instructions and guides on how to cancel charges and relationships from the list of businesses on our site, we have no affiliation with these businesses.