I just went through the motions again. Still works.
Make sure you're using the link that is currently in that spoiler above. It's one of those links that transforms into something else when you click on it. It should be www.ctshirts.com then a slash then a code with numbers and all-caps letters.
If that still doesn't work try clearing out your browser's cookies and cache, and/or using an incognito browsing mode.