The problem may have been that the books were sent in two different orders and I naively spoke to somebody at Amazon before sending them back. I got conflicting directions from the live customer support person who said a label would be sent out for the two items sent in different orders. I waited for the label to be sent, it never came, I called again and it was handled electronically. And it was still a pain to go to the post office and hand the package back to the postal worker behind the desk. I easily spent 20 minutes in line to do that.