All campaigns display aggregate stats of unsubscribes. To find out the list of contacts who have unsubscribed, go to Settings. We have added a new section called "Unsubscribes".
You can click on Unsubscribe and press "Export data". A csv file will now download with the list of all the contacts with Unsubscribes. You can now import this file into your CRM.
Information included in the data includes the Name, email, phone (when applicable) campaign and the date of the action.