Receiver’s country Customs won’t release the parcel. The last tracking status is: 境外进口海关留存待验(限制进口的物品-进口许可证丢失/不适用)
I have asked the customs to return to sender, but customs is saying that the sender has to ask from their side.
I contacted the sender, but they are saying they don’t know how to do this.
How can the sender ask the parcel to be returned? What is the process. Parcel sent by EMS China Post

UW653021468CN. Please help me with why my parcel keeps on being returned once it enters Shanghai. Why can’t it pass the custom check? What should I do to stop this cycle? This is already the 6th time again. Sender is providing no help and telling me to wait but it has not even moved from China. I’ve already contacted sender but what I want is to figure out how to break this cycle of returns. Can anyone please provide a solution for me/sender to get my parcel moving??? Thank you very much.

Dear Sir or Madam!
My parcel number is EJ272331943AU.
It had sent from Australia at 26th March. There are new purchased things from Australia and don't even open manufacturer packages including laptop and iwatch.
The Australian post didn't inform us that is not possible to receive laptop through post and we didn't know it might be rejected to receive or returned. If you look at tracking way, you can easily see the how many times my parcel sent to the SHANGKHAI post and Beijing post from the beginning. I wonder if the Australian post mistakenly sent the laptop which is not allowed to China, why China can not return it ASAP to Australia? I am a poor student who bought things with my all savings and tired of waiting for at least returted to the sender.
What should I do? When it will end? Please return my parcel to the sender.