^^ The Australian Post tracking is slow to update:
https://auspost.com.au/mypost/track/#/search
Unlike FedEx and UPS where you have constant updates, the Post Office system only updates at major points. Once the package is in the air, you won't see any updates until it's in route from your local post office to the final destination. At least that was my experience.
The cables are made to order, so it takes some time as the precision soldering cannot be rushed.
They seem pretty stand up as I had to have my cable repaired that was a fault of my own and everything went well.
The communication though can sometimes be iffy.
When I sent my cable from USA -> Australia via Post Office for repair, it takes about 3 weeks till it arrives. If it shipped out from Sydney on the 21st, you probably have another good week to wait.