I found a link to "Edit billing" by going into My products and services from the main My Adobe page then, when the page finally loaded which may take a while, it showed all my Adobe products I have ever owned.
At the bottom under product subscriptions there should be a Creative Cloud entry with a link to the right that says "Manage". When you click it you should be taken to a page that shows the subscription in more detail with billing details, along with the Edit Billing link.