For those of you who weren't able to get a code earlier from this promotion, it looks like this might be back up and working again. They have changed the method of receiving a code now to where you put in your email address and you have to put in a verification answer also. I was able to complete the form and it said that my code would be emailed to me, although I have not received the email yet.
Edit: As a follow up, I wanted to say that yes I did receive the email with a code which worked for me. So if the little "click here to redeem" button is visible at the top, you should be able to claim a free code if you need one.