Suppose you purchased a Kindle eBook and you do not like the contents. You’d probably ask your electronic librarian this question:
How Do I Return a Kindle eBook?
You have up to seven days to return a Kindle eBook you purchased from Amazon. Go into your Amazon account, click “Manage My Kindle,” locate the book you want to return from your Kindle library, look on the far right and click the drop down menu “Actions,” then “return for a refund.”
After a refund is issued you will no longer have access to the eBook.
(source: Amazon Help)