Unable to access map pack previously purchased

"I downloaded the Crimson Map Pack as part of the “14 Day – Buy and Play” program, but haven’t purchased either the War Games Map Pass or the Crimson Map Pack.

Now that the complimentary access period to the Crimson Map Pack has ended, you will no longer have access to the Crimson Map Pack unless you purchase either the War Games Map Pass or the Crimson Map Pack individually. If you do not wish to purchase this
content, and you are receiving the error “Unable to validate." Please make sure you are connected to Xbox LIVE and have the War Games Pass downloaded,” then you will need to delete the Crimson Map Pack content from your Xbox hard drive in order to continue
playing Halo 4. If you need further information on how to delete this content from your hard drive, you can check out the support article titled “Copy, move or delete Xbox saved games, profiles and avatar items.” "

Problem solved, it was a trial. Got to buy the War Games Map Pass!

Hello,

It's not possible to transfer map packs from one account to another. If these map packs were purchased on one account on the same console this account is on (and the account that purchased the content is not banned) you will be able to access those maps on
this account to.

I had to convert my payment option to pesos before I could get my map pack

The problem might lie with the region. What region are the points? Your version of Black Ops 2 is German or British? Which store are you trying to buy it off from?

.

I wish I could help more, but this isn't really my area. :-/ Try contacting Xbox Support.

Q - If I buy a Season Pass, will I get early access to the Call of Duty®: Black Ops 2 DLC Map Packs?

.

A - No, fans who purchase the Season Pass will have access to each of the Call of Duty®: Black Ops 2 DLC Map Packs on the same date as those who purchase the DLC Map Packs á la carte for their respective platform.

From the link in the first post.