Trouble disabling new user registration

I am trying to disable registration of new users for a closed membership site. Here are what I think are the relevant settings:

JFBConnect
User Creation: Full Joomla User
Automatically Link Facebook Users by Email: Yes
Email Field on Registration: Hide
Skip Joomla User Activation: No

Community Builder
Allow User Registration: same as global 'allow registration' site setting
Require Admin Approval: Yes
Require Email Confirmation: No

Joomla
Allow User Registration: No

When a user with an account clicks on the Login with Facebook button, the user is logged in and linked if not already.
When a user without an account clicks on the Login with Facebook button, a new Joomla and Community Builder User is created in an unconfirmed, waiting to be approved status.

What is the proper behavior for the second situation above? If registration is not allowed globally on the site, I would not expect new users to be created. And I would expect the user would get an "Invalid username or password" type message. Or do I have some setting incorrect?

Thanks in advance for any guidance.

Thanks for the response.

Yes, I want the Login With Facebook functionality to only be for users to login to the site, not for creating new users. Meaning that I don't want any new users created at all.