the parcel CY285558098DE arrived in Hangzhou customs on Sep 19 but your receiver has not made customs clearance. Did you write receiver's mobile phone number in the parcel? If yes, receiver should have received a text message from China Post, the message has a passcode to make online customs declaration.

first, your receiver must have a china mobile phone number, not German number

If you don't write receiver's china phone number, then you need ask receiver to go to local China Post office to make customs clearance in person. he can call china post hotline 11185 and ask for help.

It seems that you returned something to China for refund. Some bad seller doesn't make customs clearance in order to avoid refund money to buyer. If this is your case, you need avoid buying from such bad seller in future.