Hey there, That's unfortunate. You should ask Australia Post for a proof
of shipping document that shows that you sent the item, and where you
sent it. As it is click and send, they would have an electronic copy of
it. They may not give this to you, ...
In our industry (sunglasses) the reason a seller will take 4-5 days to
ship out, is because they do not have the item in stock and are
drop-shipping, or using a network of affiliates. eBay has introduce the
shipping and handling time to their listing...