China post have lost my package but I have no way of contacting them to try and resolve. Anyone know how I can speak to someone at china post?

Tracking LZ294253956CN

Hello,
My parcel has been in transit for 47 days now, and and the tracking data hasn’t changed in 41 of those days.
The sender has attempted to contact china post, however they had said to contact Australia Post and that it has arrived in Australia.
I have done that and they have no record of the package even leaving china. I’m starting to think the package has been lost and China Post is refusing to admit it.
Are you able to pinpoint to location of my parcel and provide me with an update on its condition and movement.
If not how do I lodge an official complaint about the service?
Thank you.

how can i contact china post? Lost package number RS039866065CN. Seller of the goods has closed the store. How can i get the package?
TY so much