1. Contact the seller, report the situation to them, and ask them to contact the courier to see what is going on. If the courier gives it to someone else to sign for it without your consent, resulting in the loss of the item, the courier will compensate.
2. Contact the phone number of Shentong headquarters or local (5 Zhejiang) and report the situation to their customer service, so as to have a good idea. Don't worry, this kind of thing is easy to handle.