Hi and Welcome. My Name is ***** ***** I look forward to assisting you today with your question.
Are all the books purchased from Amazon account ? If so, follow the steps below to deliver them to your Kindle.
On your computer, goto Amazon's Manage My Content and Devices site, go to this website --> http://amazon.com/myk
Log in to your account. You can find all your purchased books there. Just send or download them to your Kindle (deliver the book to your Kindle using the 'Actions...' menu to the right of the title).
If you didn't receive any books you purchased to your Kindle, then you can de-register the Kindle and re-register it to your Amazon account.
If you have any difficulty on following the steps above, please let me know and I will walk you through it.
Remember, this is not my final answer. If my solutions didn't work please don't rate me bad or poor. Instead please reply back to me and I will continue to help you until we fix the problem or you are satisfied.
If you want, I can remotely connect to your computer and help you directly to fix the Kindle issue and also recover the Telstra password ***** you.