I want to cancel a subscription but it wont give me a choice, its iCloud storage

Cancel upgraded iCloud storage by downgrading to the free 5GB plan. See instructions in: Downgrade or cancel your iCloud+ plan - Apple Support

Also see the following from that support article:

If you can't click Done, make sure you are signed in with the same Apple ID as your iCloud storage plan. You can also try following these steps on a different device. If you still need help, contact Apple Support.