I put the code in on the webside and signed up but when i click apply it says "You must logged into your xbox live account to apply double xp! Anyone know what to do?
There is a “Sign in” button for Xbox LIVE above your available matches/double XP history.
Click the dashboard button at the top right of dewxp.com. There on the dash page you will find a green button that says something about xbl. When you click it dewxp will re-direct you to xbox.coms sign-in page; log in to your xbox live account then add the points again.
Hope this helped 
- HSM
My double xp doesn’t seem to be working atm, anyone else. I applied 6 matches with nothing, was working fine yesterday.