January 8, 2013 No Comments FREE 20 oz Coke Zero at Thorntons Check out this week’s Fan Exclusive Coupon: FREE 20 oz Coke Zero! You can print the coupon by clicking the Welcome tab at the top of the Thorntons Fan Page. Coupon valid January 8 – 14, 2013. Locations. FREE 20 oz Coke Zero at Thorntons – EXPIRED Facebook Twitter Add Comment Notify me of follow-up comments by email. Notify me of new posts by email.