1. With all the tracking I have done on your parcel, I have a few options.
The last tracking is this:
Number: LX975420615CN
Package Status: In Transit
Destination Country: United Kingdom
Origin Country: China
2016-09-21 21:36 Suzhou city, leave sent to London's Heathrow airport hub city, Suzhou city (transit)
2016-09-21 03:03 Suzhou city, reach the hub center in Suzhou (transfer)
2016-09-21 02:15 Wuxi city, leaving Wuxi, Suzhou city
2016-09-20 21:02 Wuxi, Wuxi received the express and logistics market (embrace cast member name: Sales Department, Tel:)

2. I was not able to confirm by tracking that the parcel is On Route to UK. It might be that the EMS in Suzhou forgot to put it in the China Post system.

3. When I see this:
2016-09-21 21:36 Suzhou city, leave sent to London's Heathrow airport hub city, Suzhou city (transit)
It's telling me that the parcel is transferring to another place maybe a bigger Airfield that fly to UK or even to Suzhou Airfield.

4. Has anything happen to your parcel, left in a corner, lost those are possibility. Has your parcel really departed from China, and, UK Post did not yet scan your parcel, that could be a possibility.

5. Your parcel is an E Packet parcel and normally it take between 6 to 12 working days to be deliver excluding the time spent at the China and UK Customs. As of today your parcel has been on the road for 11 days.

6. May I suggest you contact the seller to find out if your parcel is still in China. But unfortunately China this week is on a National holiday so very few person are working even China Post is at minimal staff.

Hope this help.