you can contact pottermore's shop support, but they dont give alot of refunds. I think only if you accidently multiple purchase. otherwise, because of the more open format, people could cheat, download the books, then get a refund, and still have them.
I have the paper books and want the ebook versions also. Just am waiting until my birthday to get the ebook versions. Can't wait to be able to have all these huge books in one leightwweught version. Also, am looking forward to being able to highlight passages and makes notes as I go along.
Figure my paper versions will go to my kids once they are a little older.