Water damage to package deliver by The Courier Guy

I received a package that was water damaged. On delivery the box was delivered to me was wet on the outside. When I asked the driver from Courier Guy about it he stated that his delivery van was wet inside. I opened the box while the diver was still with me and one of the items inside was damaged by the water. I took photos and logged a complaint with The Courier Guy company and their reply was that the claim was rejected. The reason they gave was and I copy their reply: "Our investigation could not pick up any mishandling at all I am so sorry". It is difficult to understand why there was not mishandling of a package if the employee delivering the item acknowledge that the water damage occurred in his delivary vehicle and there is clear evidence of water damage.