This used to work in the past. Not sure if it still does. But if you log into bbid.com and change the email address associated to a different one you should receive an email that contains the same link as the original email to delete your BBID. You may get an Auth email first then a confirm email once auth'd.
Check both emails for the link.
If not, you can call BlackBerry support and they have a process internally to delete it from the back end. Refer them to internal notes on
http://www.blackberry.com/btsc/KB25464
Z10STL100-3/10.3.0.710