I emailed them to opt out of their calls. The following is from their website, surveysampling.com:
To opt-out, please email us at
[email protected] (please include the phone number in the body of the email) or call 866-360-9563 to be placed on our no-contact list. If you would like to speak to someone about the call you received, you may contact us toll-free at 866-360-9678.