An email has been sent to those who originally registered for Shell Go+ using their Facebook account. As mentioned in the email, to keep your Shell Go+ account, you will need to use the email address linked to your Facebook account and create a Go+ account password.
This email was sent 15th June and contains a link to create a Go+ account password. From here, you will be sent to a ‘Forgot Password’ screen where you'll need to enter the email address linked to your Facebook account which will then start the process to create a new password for Go+.