My experience of Yamiya is very well packed gods. I doubt it can be a shipping issue.
I ordered a set of Lotus Root pipes, 1 of them was wrong model of pipe, HM300 which was very obvious. No problem to get a new correct #3 pipe from Yamiya and return the wrong since they have seen photos. Issues with customs here that needed all old paperwork to accept the new part as free.
The pipe I got was not perfect, chrome very thin, partly missing on inside where there is a dent and hole for rear bolt not visible when mounted. I did not want to restart a complaint again with all work with customs. Painted the area with engine paint to avoid future rust
This indicate that they do not inspect the packages before shipping. The fenders might have been stored in their own boxes waiting to be shipped.
I ordered a NOS tacho from CMSNL once, I got an email that it had a dent and I could get it cheaper. They inspect the gods before shipping. I canceled the order and got refund.
DSS in UK shipped a K2 replica seat for 135 Pounds + 20% VAT. When I inspected the seat I found that one welded thread insert for hinge was missing. Mailed them with photo and told them how much a return will cost me. I got 100 pound in refund an kept the seat I could fix.
There are very good guys out there.
Last action is to contact PayPal quickly and explain the situation. This is not small money.
Damaged gods by shipping must have corresponding damages on boxes. The shipped boxes will have fresh shipping labels that should be damaged too if true. Boxes can have marks done before shipping.
If damaged due to shipping... still Yamiya's responsibility to pack it good to avoid shipping damages. Except if a truck has mangled it and similar.
Photos on boxes and parts tell the story.