Hello, I had a similar experience last summer when I shipped a pair of nearly new B&W 804 speakers and an HTM-2 Center speaker from Northern California to Amarillo, TX. All three items were in the original factory double boxes.
The three items were separated enroute. One 804 arrived in the morning - undamaged - and was signed for by a friend of the recipient. The other 804 and the HTM-2 arrived in the afternoon and were left with a neighbor; nobody signed for these. This 804 was damaged - external tweeter crushed, grille frame crushed, and the veneer damaged in several places - no damage to structure or midrange / bass drivers. The box looked like it had been dropped from several feet (at least) onto a top corner!
When I emailed Audiogon to find out what my responsibilities were, they told I had to pay for a return of the shipment, refund all of the buyer's money, including shipping, PayPal fees, and purchase price, and that I was to file the claim with FedEx. Depressing, severely. Essentially he was to be held harmless. When I offered this to the buyer (through clenched teeth) he told me he wanted to keep the speakers and file the claim himself. Whew!
He filed a claim for full replacement of the pair, which FedEx declined to pay. He shipped the damaged speaker to their claims adjustment center for assessment. When they returned it to him, it had sustained yet more damage!
Eventually, he was able to obtain payment from FedEx for a satisfactory repair performed at B&W's American Service Center. It took at least to months for FedEx to pay the claim. If I were cynical, I'd say they drag it out in the hope that you will give up.
I used FedEx because I thought their service was superior to UPS. Turns out, as you are no doubt finding out, they simply charge a little less, but can be just as careless.
In the end, this actually turned out OK, but it took a fair amount of perseverance.