Lost package

My mail delivery guy has been hit or miss lately with deliveries. I have a Rhodesian Ridgeback and he will just take my packages to the PO of leave them by the road where a few times the package was actually on the actual road. This time we ordered a RODI system. Very expensive. I'm talking hundreds of dollars. Well I was watching for it to be delivered because I was tracking it and knew it would come that day. It showed as delivered so I looked and nothing was out there. It said delivered in the mailbox. Our mailbox is small and this is an actual box with an RODI system inside so it's not a small box. I called the Post office. The Post mater told me to wait and see if it gets delivered the next day. It didn't. So on Monday I called the Post Master again and he gave me the driver's phone number and told me to call him. I called and the driver said he remembered putting the package by the mail box next to the road. It's gone. Amazon seller is not going to refund it because it says delivered. The post office tells us to contact Amazon. We are out a lot of money!! I"m not happy. Is there anything I can do?