Is there any way to contact 北京国际邮件处理中心 (Beijing International Mail Processing Center), either by phone or by email?

As far as I know there are 5 of such Centers in Beijing, and my parcel is stuck since April 21st in one of those centers.

I'd like to contact them directly to ask when my parcel can be delivered, but I didn't find any phone number on baidu. I went to Beijing International Post Office but I had no luck. They told me my parcel was in one of the 北京国际邮件处理中心, but they couldn't give me any contact.

The locations are:

http://map.baidu.com/?newmap=1&s=con%26wd%3D%E5%8C%97%E4%BA%AC%E5%9B%BD%E9%99%85%E9%82%AE%E4%BB%B6%E5%A4%84%E7%90%86%E4%B8%AD%E5%BF%83%26c%3D131&from=alamap&tpl=mapdots

I need their direct contact (phone or email) to inquire about my parcel. Thanks.

I called 11183 and 11185 many times but they couldn't give me any information. All they say is "This is the post office so we can not track it".

I asked them to get me in touch with the Beijing International Mail processing Centers, but they keep telling me that "they are not allowed to give me their phone numbers" or that "they have no phone numbers".

Nederland Post can not continue the investigation for the same reason: they can not get any answer from Beijing International Mail processing Centers, because apparently they have no any contact such as emails or phone numbers. If they contact China Post, then China Post can not provide them any information. What to do?