I once filed a damage to claim to Canada post, both me and the buyer had to do our part. The buyer agree that my item was was more than well packaged.
I had paid extra for insurance (up to $900), in they end, the deemed my packaging inadequate and did not cover anything! So the $900 item was destroyed and I had to refund the client. $ 1,800 gone because of them. In the end, they accepted to refund the $35 shipping cost.