My credit card merchant requires the same. They put it to me in black and white that any item protested of non-delivery would have to have a signature required as proof. I like to use FedEx ground sometimes because you get $100 free insurance and you can get a signature specific for extra money, costs the most but then you have the proof. But yes it sucks and also sucks that he has the merchandise.

I did one time tell the customer who claimed non-delivery that I will fill out the form for a lost or pilfered package at the post office even though it had delivery confirmation, and make the mail person swear he delivered it to your house. If he doesn't swear to it then the mail person stole it and he will be dealt with. The guy got the idea it was either him or the mail-person and emailed me same day oh I found the package. I only did that one time and it worked. I do realize in a few cases the mail-person can leave it on the porch and then it can be robbed. But the mail-person would be bale to recall if he handed it to a person of the household. And yes they have a form (at least they did a couple years ago) you can still insist and fill out. Then I would get the mail-person's statement and send a copy to eBay/PayPal and then say cc: to "my lawyer" and see if they give. Worth a try but I know sometimes it's better to bury it, life is too short and not worth the aggravation.