http://track-chinapost.com/startairmail.php shows the number is invalid. Your seller has not shipped anything yet. If you get the number more than 3 business days, you should be cautious of fraud.

Which website did you buy from?

Quote from FW on March 1, 2018, 01:08
I purchased from iOffer!!!

Can you please check these tracking numbers as well:
LH207158057CN
LH207133523CN
LH207299443CN
LX762936127CN

In there website it say estimated delivery March 10 - March 30, 2018

Can you please advise?

You can track these numbers yourself here: http://track-chinapost.com/startems.php

Once a parcel is actually given to the post office, the tracking number will start working within 48 hours. So if you only ordered within the last few days, it won't be unusual for tracking numbers to not be working yet. However if the seller tells you they've shipped the parcel, and the tracking still isn't working 3-4 days later, then they are most likely lying to you.

These kinds of parcels (ePacket, tracking number starting with L) tend to take 2-3 weeks to arrive in Australia, so the timeline they've given you is accurate.

iOffer is a risky site, many users here have had problems with them.