I honestly want to say this site is just a really convincing scam, after sending an email that the code was already redeemed I got one back asking for a screenshot of the error. After replying with the screenshot I was mailed back that I was the only person in their database to receive the code. Sent an email yesterday with the code asking to confirm if the code was in fact the one it showed in the database and haven't received a reply. A fair number of other people are claiming they haven't even received an email with their code at all or their code was already redeemed and they haven't been given a new one.
After all the people saying theirs worked or they received a new one I figured that people getting codes that didn't work was just an honest mistake and didn't think to look into it deeper. First time I've made that mistake, never again.
I figured I'd put the word out at all the places I saw the deal mentioned.
Finally got a working code about ten minutes after posting this.