no need to sign for as damaged, you may not realise until you open the package,
I got Parcels2go to pay up in full for a 5 wheel refurb when the managed to drop a wheel hard enough that the two layers of cardboard, filmwrap and 5mm of high density foam around the rim was cut through and the paint chipped off the rim on one they delivered. the others all had marks and chips as well.
keep at them, photo everything, keep packaging, get the sender to send photos of items before shipping (even if they are not the ones he sent you!). even without specific insurance the courier has to cover damage whilst in their care.