[tadol]

I think that you are not signing that the guitar arrived undamaged, but that the box arrived undamaged. When you sign for the receipt of a box, you need to note any exterior damage that may indicate damage to the contents. Many drivers will note that, some may ask you to open the box to check for any damage to contents, and if none is evident, they will note that. For instance, if the cardboard shipping box is torn, and you want to note that on the receiver, they may ask you to open it and check the case. If the case itself is unblemished, and the guitar shows no obvious signs of damage, they will note that as well.They frequently note the location of the exterior damage, and its correlation the the item inside.

All the shipper is interested in is proving that the item being shipped arrived in as good condition as when they picked it up. With no obvious signs of external damage, you're going to have a hard time proving they are responsible. Much better off returning it to the sender, getting your money back, and let them deal with it. But if there are obvious external signs, and you did not note them when you signed for it, you may have some problems.

If they just left the box on your porch and you didn't sign, you need to work closely with the shipper to get it resolved -

Good luck - Tad