Microsoft Store Purchasing

I am trying to purchase a game called "Batman: Arkham Collection" since it is on sale for over half price but whenever I press the buy button It says "Oops. Not sure what happened there. Please try again later" so after it says that a couple times I go to bed and the next day which is today it still says that. If this info helps I am using a xbox one s. I would appreciate somebody to help me with the problem as I really like batman arkham games. Have a good week

:)