can't delete user

can't delete user

I am trying to cancel my account and am following the instructions to delete domain (done) and delete organziation, It won't let me delete organziation until users are all deleted.  When I go to USER DETAILS and try to delete accounts, I am unable to delete the accounts (one if superuser, one is not).  I click the check box for the user and hit the delete button, it gives me the warning and asks for the password, but then the account is still there and I can not move forward to deleting the organization.  Why can't I delete the user?