Error on my three month xbox live gold membership

His information is correct. It's per the terms and conditions of the offer -
rewards.xbox.com/terms-and-conditions

Renew 12-month Xbox Live Gold Membership: Available only to participants who are Xbox Live Gold members renewing their Xbox Live Gold membership as of the Program start date. Participants must be Xbox Live Gold members
at the time of renewal. Xbox Live Free members and Xbox Live Trial Gold members purchasing a membership are not eligible. Each 12-month Xbox Live Gold membership purchased during the Program Period will earn three thousand (3,000) Rewards Credits, up to a
maximum of three thousand (3,000) Rewards Credits during a twelve (12) month period. To renew your Xbox Live Gold membership,either redeem a Prepaid Live Gold membership, purchase a membership from your Xbox 360 or Xbox One console’s Dashboard,
or visithttp://www.xbox.com/en-US/Live/JoinLive/Membership during the Program Period.
Users of Prepaid Live Gold memberships will be credited upon actual renewal date, defined as the time the previous membership would have expired.

Yes, they are cumulative. You can stack Xbox Live Gold time for up to 3 years (36 months). You can redeem all three cards and it will extend your Gold membership for 18 months.

Hello Wisefr0g,

After reviewing your account, your Gold subscription for the last three months was a promotional, discounted subscription. As mentioned in the FAQ, promotional subscriptions are not eligible for Rewards:

My Xbox Live Rewards account is not recognizing my Xbox Live Gold membership. What should I do?



Xbox Live Rewards can only recognize paid monthly or yearly standard, non-promotional Xbox Live Gold memberships. If you have a different type of membership, we may not be able to recognize you as an Xbox Live Rewards Gold member.

Yes, it's possible:



Q: Can I add existing Xbox LIVE Gold members to my Family Pack? For example, my kids are already Xbox LIVE Gold members.

A: Yes. When an existing Xbox LIVE Gold member is added to a Family Pack, the remaining time on their Gold membership benefits the whole family! For every two months remaining on their current Gold membership, the entire family receives an extra month of
Xbox LIVE Gold. For example, if your child has six months remaining on their existing Xbox LIVE Gold membership, when you add him/her to your Family Pack, all four of the individual Xbox LIVE Gold accounts available in your Family Pack will be extended by
an additional three months. If you have two children who have four and six months of Gold remaining, respectively, on their existing Xbox LIVE Gold subscriptions, all four of the individual Xbox LIVE Gold accounts available in your Family Pack will be extended
by an additional five months.



You can find more information here -
www.xbox.com/.../FamilyPackFAQ

Hey there! Your question is explained on the FAQ page:
http://support.xbox.com/en-US/billing-and-subscriptions/account-management/how-to-join-family-pack

"

Gold Family Pack discounts and membership extensions

If you currently have an Xbox LIVE Gold Membership, you will get a discount on your Gold Family Pack membership based on how many months remain on your existing Gold Membership.

The discount varies by region, and is calculated by first taking the price of an Xbox LIVE Gold 12-month membership divided by 12 months (Gold monthly rate). The Gold Family Pack discount that you receive is the Gold monthly rate, multiplied by the number
of months left on your existing Gold membership (rounded up to the next full month), then subtracted from your purchase price.

Note Your Gold Family Pack membership starts on date of your purchase. Your credit card is charged immediately, after any discounts are applied.

Do I get a discount when I add existing Xbox Gold members to my Family Pack?

Yes. When an existing Xbox LIVE Gold member is added to a Family Pack, remaining membership time is added to the Family Pack membership. For every two months remaining on their current Gold membership, the entire family receives an extra month of Xbox LIVE
Gold. For example, if your child has six months remaining on his or her existing Xbox LIVE Gold membership, when you add him or her to your Family Pack, your Family Pack membership is extended by three months."