I've had a few expensive A-Z claims recently where the customer claims they haven't received it and Amazon has refunded them.

"The customer reported an issue with delivery. In this case, the tracking information indicates 'delivered', but the customer did not receive the package. Because you provided sufficient information that proves the order was actually received by the customer, we will not count the claim against your Order Defect Rate."

Parcel was signed for, Amazon states there's sufficient information, so how on Earth am I supposed to protect myself?