Send them a deletion request using the form link (or use e-mail). Include your username and e-mail known at Current.
Read more on http://current.com/s/faq.htm#cancel_account
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.