Sign up email doesn’t show up on MailChimp

Sign up email doesn’t show up on MailChimp. The plugin itself looks promising but there’s two main problems, viz:
1. When someone clicked on the subscribe button, a long message “You Have Successfully Subscribed to the Newsletter” appears for a very long time.
2. When someone clicked on the subscribe button, the email was saved only on the plugin ‘Subscribe list’ and not on the MailChimp list, this is very disappointing because I rely a lot on Mailchimp.

If you’re ready to fix this issues asap. I will post a positive review.