be forceful!

Tell the seller you have no idea who signed the parcel. It is seller's
responsibility to get the good to your hand. As long as you don't
received the good, you wouldn't pay for it. If the seller refuses
to put effort to find the parcel, call your credit company to
request a charge back. When seller informs UPS the parcel is lost,
UPS has to find it (or find the responsible party to recover its lose)
or eat the cost. That is what shipping insurence is for.

How old are you? Learn to make a forceful point and stand up for yourself.