I suggest using the website marketplace where it's available to purchase. https://www.microsoft.com/en-us/store/p/destiny-rise-of-iron/c1cjbxdgpgn5 It will show it's only available as part of a bundle if you're not logged in. Once you log in at the top right like normal, it should then show that it's available for $29.99 (or whatever your local currency is, I assume). If it still only shows that it's available as part of a bundle and does not give you a price, then you need to contact Microsoft and walk them through doing it for you because their system is saying you do not own Expansion I, Expansion II, and The Taken King on Xbox One.