Hello, I’m Nathan, and I’ll be assisting you today. My livelihood depends on your positive feedback, so your satisfaction is my highest priority.
Sorry to hear you’re having trouble.
This may happen if you are only using the kindle app in a demo mode.
Go into the settings (tap at the top left corner for the menu) and be sure it is registered to an amazon account.
You can also, once registered, make your book purchases on the computer from amazon.com: http://amzn.to/1XopUMZ
When you make a purchase from the same account your kindle/app is linked to, it will show up on the kindle/ipad automatically.
Do you need more help with this?