2. First hand delivery, first hand proofing. Or don't give it to him, keep the broken machine for yourself, and it can be used as evidence then. Actually, you don't have to look for it at all. It's none of your business.

You didn't sign for it, which means they didn't send it. Whoever lost it, you didn't lose it anyway. You just paid the money and didn't get the goods. You paid the money, and the sales contract has been established, but the other party failed to fulfill the contractual obligations on time according to the contract. They are responsible for the contract, so they should repay the purchase price and liquidated damages.

Ps: What did you sign for? Didn't you bring anyone? They can be your witnesses. This matter is easy to handle. The facts are clear and the evidence is sufficient. If you go to court, you only need a simple procedure.