i saw this and checked mine, it also was not there, chatting with them they sent me the email about the credit but never sent applied them to my account, good thing now is they do not expire
version 10.6.0.200
build 12.0.155.0
if you click on the amazon app store under amazon video, go to the bottom and click on appstore settings, there you can add a appstore shortcut icon to your home screen