Purchased THX with coupon and now no code to unlock

I purchased some Razor headphones. I had a code to unlock 7.1. While using code I had an offer for half of THX. I purchased THX with code and got half off. I went to download link on web page it said Demo. I did not get a code to use THX. NO email or other. I am asked for code to unlock my purchase of THX. I used code I got with headphones and that did not work. I bought THX and I cannot use it with my headphones. Please help.