My tracking number: RM653039203CN
The last update is from 19 Nov and says "郑州Transit Station import customs cleared (domestic transit )"
What does it mean? Is my parcel still in China?

Quote from Lesdier on December 3, 2015, 19:12
Yesterday expect my package arrived but still did not receive today , I could tell me what has happened

Estimated delivery Wed, Dec 02 - Wed, Dec 16
Tracking number:Tracking numberLK690163451CN

New For Samsung Galaxy S3 i9300 Full Lcd Touch Screen Glass Digitizer Frame Blue
( 171039998748 )

http://track-chinapost.com/startusa.php shows the parcel has not enter USPS system yet.

Quote from banaszi on December 4, 2015, 17:58
How long it can take to enter this USPS system? I mailed to seller and he said that my parcel is somewhere between China and Poland

i am talking about LK690163451CN not your parcel. Your parcel is china post register mail to Poland, USPS is United States Parcel service.

http://track-chinapost.com/startairmail.php shows RM653039203CN status as "郑州Transit Station import customs cleared (domestic transit )".

this is a very bad sign which means the parcel was rejected by 郑州 customs. Obviously your seller is lying, you can not get the parcel anymore.

If I were you, I will open dispute for non-arrival parcel asap.