This is awful, I'm sorry to see what has happened and how poorly eBay and other customer service / managers have handled getting back to you about your queries.

There was something you said:

>  I uploaded tracking details from both ebay & Australia Post website but somehow eBay system didn't send it through

This could be why you you didn't receive seller protection, despite there being some kind of technical error by the sound of it.

The only thing I can suggest at this stage is to go back to eBay and ask them about the seller protection again.  Tell them you did everything required of you and insist they check off each item needed one by one.  And tell them you can provide everything directly to them if required, as I've been given a direct email address in the past (many years ago) to send evidence.