We got this error in the office while testing the purchase path before the game came out. It seemed like entering incorrect information more than once caused it to deny the credit card even when the info was correct (but I'm not sure about that). That might be why it says to wait 24 hours.
This may be a dumb question, but are you sure the address you're typing in matches the credit card you're trying to use? If you haven't already, get out a bill for your credit card and make sure you're entering the address exactly as it appears on your bill.
Anyway, please send an email to support@telltalegames.com and customer service will look into this for you. There should be an order number on the shopping cart page, before you get that error -- include that in your email, along with your full name and the email address you're using.
Thanks for being patient... we'll get this straightened out.
