Amazon’s policy for return of Kindle ebooks states:
Books you purchase from the Kindle Store are eligible for return and refund if we receive your request within seven days of the date of purchase.
Unfortunately, this policy hurts authors because a reader can download a book, read it and then return it. It also increases the opportunity for a book to be pirated: an ebook pirate can purchase the book, defeat the DRM protection, then obtain a refund while keeping the book and sharing it on copyright infringement websites.
Amazon has a track record of indifference toward independent authors. (For example, its deliberately vague content guidelines allow them to discriminate against erotic and other authors at whim.) Customer service with regard to the Kindle Direct Publishing program is all but nonexistent, and it’s often next to impossible to even speak with an actual Amazon representative regarding issues that arise. Thus, their policies in these areas, including book returns, are unlikely to change.
Thus, the onus is on you, the reader, to do the right thing in supporting independent authors. When you purchase a book and return it, you’re taking away from your favorite authors. If you buy a book, don’t return it… own it.