The book takes a coincell (CR2032) battery that is secured with a screw. The battery should last 5-10 years. To remove it, you can undo the flap in the back, remove the safety screw, and then slide the battery out with a plastic tool or if you have really grippy fingers.
Send me an email, and I'll look up the order status, and will send a replacement if necessary.
If you can't get the AND page to light up. Try pressing both buttons at the same time.
If two of the internal pages are acting the same, then the most likely cause is that one of the holes didn't get punched out all the way. In which case you should be able to just punch it out with a pencil or something.
Otherwise, reach out to me via email or through the contact-us page and I'll get you squared away with a replacement.