Yeah, I’ve had the same thing several times. The problem is that there are many companies delivering in China. However, if you have the tracking or post number (your mum should have received one from USPS), you can go to any China Post office and they can check it in their system. One of my packages sent from Holland was tracked down this way, they said it was send back to Holland via Shanghai after being found ‘undeliverable’. It never arrived in Holland, though. If you don’t have a tracking number, visit the ‘package’ post office near your house. It is not the same as the normal China post office. Ask people in your compound where they go to pick up their packages. Then go there, tell them you are waiting for a package and ask them if you can (with them) check the pile of packages that are waiting to be picked up. I found several packages of me and also of friends like this. Another option is to ask the customs office, since apparently everyone needs to have some kind of customs id number since a few months in order to receive a package. Perhaps it is stuck there and cannot be cleared because you did not provide the number, and they don’t know how to contact you since there is no phone number. It will take some effort to find out where this customs office is, though, I have no idea. Good luck!