If you are simply looking to lock down only the completed surveys but continue to have unanswered surveys remain open, please visit this article.
When you are ready to shut down your surveys, you must notify firstname.lastname@example.org. CrowdOx has the ability to close down all configurations that are live, or specific configurations that you no longer want to be open, so please clarify your intentions inside the email.
Once CrowdOx has closed down the live configurations, backers will no longer be able to complete their surveys.
For more information about exporting your data from CrowdOx, please visit this article.