I have two apple ids. One says it’s for media and purchases and the other one says it’s for iCloud storage. When I purchased Apple One I purchased it with my Apple ID that’s us for purchases but I wasn’t able to access it he increased iCloud storage.

If you do not see the upgrade try different ways:

Click here --> https://support.apple.com/HT204247 --> Check to see how much iCloud storage you have

Mac computer System Preferences > iCloud > bottom right > Manage

You can also try restarting your device.

If it still won't show:

If you still have problems, click here --> https://support.apple.com/choose-country-region/ Select your country, then a product.

If you subscribe to Apple One and use a different Apple ID for iCloud storage - Apple Support

I tried to follow the instructions on that page, on my iPhone, but I see two entries with my same email address; one (already selected) is marked "media and purchases account", and the other is marked "iCloud account". When I select the "iCloud account" one, I can't continue because the blue "Use This Account" button is still greyed out.

Thank you. I was able to see the other email address in the "Manage iCloud Storage Accounts" screen, once I logged into the account I used to purchase Apple One and changed the contact email addresses. I was then able to switch which account to use the Apple One storage with.

If they have the same email address, they are the same Apple ID. Since you already using that email address, you are already signed in.

If I'm correctly signed in, why do I still show as having only 200 GB of storage instead of the 2 TB from the Apple One subscription?

I used https://appleid.apple.com to log into the account and then I modified the "reachable at" email addresses (removed the one that was confusing the "Manage iCloud Storage Accounts" screen).