They told you that the Post Office would automatically deny the claim because the box was intact? That's not how it works. They would have to present the unit with the original paperwork to their local Post Office and the clerk would have to make an assessment as to how well the item was packed. That's standard procedure. Perhaps they don't want to do that. If a claim is denied there are several levels of appeal up to and including a consumer advocate at Postal HQ.
Insist that a claim be filed. You are not being given reliable information.
Insist that a claim be filed. You are not being given reliable information.