I have made an order at AliExpress website and my package arrived from China to Italy two days ago, but the goods in the box are all smashed out. I have informed the seller on AliExpress about it, but it is most definitely not their fault. I would like to complain to the courier.

I can not figure out how to sign a complaint to China EMS. Does somebody have information on how to do that and what is the procedure generally? Do I need to send to them the photos or do I need to go to a local post office to verify the broken package?