You are still advertising the $15 for 12 deal on your website and app. Why won't it let me apply it on the payments page?
Have you activated with Visible already, or is this on an account you’re trying to set up?
Were you trying to stack promos or signup discount from a third party link? Now that the promo is expired, the only way you can try to add it is via customer care. They may or may not be able to help you.