No mention anywhere on how to delete your account.
Drom them an email at firstname.lastname@example.org and politely them to delete your account. Tell them they are blacklisted on AccountKiller.
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.