1. This is the full tracking of your parcel:
China Post Register Air Mail Tracking System
Parcel No.CP250949779CN tracking result
2016-08-30 15:10:14.0 秦皇岛Transit Station export security scan
2016-08-30 15:20:27.0 秦皇岛Transit Station export customs scan (domestic transit )
2016-09-02 08:33:57.0 Beijing Transit Station export security scan
2016-09-02 12:48:06.0 Beijing Transit Station export customs cleared
2016-09-02 23:31:00.0 arrive Beijing Airport
2016-09-02 23:57:11.0 leaving Beijing Airport going to next airport/seaport
2016-09-03 15:33:50.0 Beijing Transit Station export security scan ,remark (rejected )
2016-09-04 08:44:34.0 Beijing Transit Station rejected ,remark (D)
2016-09-04 08:44:37.0 Beijing Transit Station import customs cleared (domestic transit )

2. May I suggest you read this:

What can I do if tracking result shows “rejected” or “Safety Check Rejected” ?

3. May I also suggest you contact seller as soon as possible and give him the above tracking and tell him the parcel was rejected and see what he will tell you. He might be able to call China Post to find out exactly why the parcel was rejected.

Hope this help.