Two months

hello fa1lur3tocompl1y, sorry to hear about your issue purchasing the promotion. Please login to the Microsoft Billing site here to make sure that you have your billing and payment details exactly the same as they are showing on your credit/debit card.
Also, please make sure that you do not have any sort of expired payment method on the account. These sorts of problems can also happen if the account is in a delinquent status, if it was you will see a notice when you login to the billing site. If after checking
into all of this and you're still unable to take advantage of the $2 for 2 months deal then you will need to contact phone support.

Yeah it’s not for two different months it’s one month charged twice. That’s it there’s no two months just the one month. October 23rd is when it expires.

There are two more DLCs planned for the next two months, so there wont be one for at least two months lol.

Hello Cryptic Flair,

Keep in mind that purchases that apply to an offer do not also apply to MyVIP, as specified in our FAQ:

What type of Rewards can I earn?

In addition to our special events and offers, there are two easy ways to earn Rewards Credits each month; by completing missions or special offers, or with a MyVIP Star Rank. To see current
missions, visit the MyMissions page. For more details, please see the Terms and Conditions. Don't forget to check back often to see what's new, as missions are updated frequently!

To learn more about your MyVIP Star Rank, which gives you a percentage back on what you buy in the Xbox Store, visit the MyRewards page. Once you have earned at least 1 Star, you'll start earning each month
based on your qualifying purchases from the previous month.

Please note: Xbox Live Rewards members may not earn Rewards Credits for multiple offers based on performing the same action. For example, your purchases made to complete a monthly mission won't also be eligible for MyVIP.

Since you opted in to the Simply Rewarding offer in March, your purchases went towards that offer and not MyVIP. Regarding your purchases in April, we have delayed payback for that month due to an issue affecting some of our preview program members. Once
we resolve this issue, you will see Credits pending for April MyVIP in your account. Apologies for the inconvenience.

Greetings, Jewblob! I've got a response out to you here:
forums.xbox.com/.../245029.aspx. However, it seems like phone support was able to help you make the purchase. Since they were able to do this the situation should be sorted out. Let us know if the problem persists when you make your next purchase! I'm here
if you have any further questions.