My parcel is stuck in customs office since 1 month

item No Year Status Location Destination Country Date
CC041311170NL 2014 Departure from outward office of exchange NLAMSA 20140417 1457
CC041311170NL 2014 Import Customs Scan Beijing 20140421 1226
CC041311170NL 2014 Import Security Scan Beijing 20140421 1348

Don't know what to do. Called 11185 and 11183 several times and nobody seems able to tell me where my parcel is, and whether I can get it or not. I live in Fuzhou city.

The parcel is a registered mail sent from Holland by TNT , insured for 5500 Euro. It contains rare stamps and postcards (no batteries inside). I didn't buy them, but a Museum in Holland lent us such material for an exhibition in China, with the promise that we will return the material to the Museum after the exhibition will be over.

The real value of the contents is around 4000 Euro. There are some unique items in the parcel and the Museum is now worried that they might get lost.

I have regularly received other 20 times such kind of material from the same museum, but I don't know why this time the parcel has been stuck at the Customs Office for such a long time. I and my colleagues called 11185 and 11183 at least 30 times these days but no one could tell us the thereabouts of the parcel. TNT Holland and the sender can not open a dispute because they haven't got any answer from China Post.

What should I do?