However, what you need to do now is to let the salesman who signed for it confirm that it was not counted clearly at that time and the goods were not received. If the public security organ can't confirm that the goods were lost on the road, then you can't say anything.
As for the risk of loss of goods, even if your store bears the responsibility, it cannot be borne by the clerk. You are a duty behavior and should be borne by the unit.