My wife and I share a PC. When I go to "login Amazon Kindle", her account comes up and I can't see where she can log out so I can log in. More bizzarely I received a confirmation email re my latest purchase (purchased through the Kindle store on my device) - the confirmation came in to my email. I clicked "Customer Service" in the email sent to me and it logged me into wife's account. I need to work out the log out/log in protocol but I also need to complain about the purchase. Any ideas?