Xbox Live 12 Months Gold Subscription Card Global offers you:
Multiplayer gaming - connect with your friends and play your favorite games together
Online chat - talk to you friends on a voicechat, even across platforms
New games for free - subscribers regularly get access to carefully selected games free of charge, to augment their libraries
Great deals - Xbox live Gold subscribers get great discounts on the hottest titles

How to activate 12 Months Xbox Live Gold Membership Card?
Visit this address: http://www.xbox.com/redeemcode
Sign in with your Microsoft account credentials
Enter the 25-character code and Confirm

You can find additional support for your Xbox Live account here: https://support.xbox.com/contact-us