To delete your account, contact the support team.
Fill out the email form found here: http://help.surveymonkey.com/contact-us
Please include in your message that you confirm you would like the account permanently deleted or disassociated which will clear the data and free up the username for other future users. This action can’t be undone! In these requests, please include your username “I confirm I’d like (my username) permanently deleted/disassociated.”