You can use the skittles method. Go to ssl.skittles.com and use the code 45qs9. Fill in the information accordingly. Use alias emails so you can do it multiple times. For the address use a restaurant's address in your location. Make sure you're older than 18 and that you click "I do not have Xbox live". After you get your first code clear your browsers cache and close it. Reopen your browser and repeat the steps with another alias email. Mail.com makes it easy to create up to 10 alias emails.

Hope this helps!