http://track-chinapost.com/startairmail.php shows LS307546845CN was shipped from Shenzhen to USA on Apr 18. it was sent to Shenzhen airport on April 24 and is still in Shenzhen airport waiting for flight to USA.

to stop covid19 virus spreading, china have cancel more than 90% international airlines. China Post highly depends on such passenger airlines to carry parcels. Many parcels shipped in Feb are still in China airport. So you might have long time to wait. Once parcel arrives USA, usps.com will show arrival info.

If your buyer protection is expiring, you need open dispute for refund first. If you get the parcel in future, you can pay back the money to seller.