The demo data is included with the theme bundle. You should see a file named sample-data.xml in the top folder of the extracted contents. It’s hard to miss it.
Will like this work for you? –
http://wordpress.org/plugins/contact-form-7-autoresponder-addon-plugin/
It helps add the contact email to MailChimp subscription and the user will need to verify their email in order to be added to the MailChimp list.