We don’t have control over money transactions. Apple does that themselves. They handle it all from purchases, making changes and canceling subscriptions.
Apple has recently improved user's access:
Their instructions are located here:
About Video Storage: Free users have less storage than Pro users. Most folks clean up their "Videos & Pictures" pages before Pro expires.
-Download and save the videos that you want to keep.
-Delete videos to free up space. There is a "Delete all unstarred videos" option in Video Settings.