Parcel ****** or undelivered? You tell me..

What happened if the customer has the delivery note and the courier drove off with the parcel? All because he came through the gate unannounced and then was to impatient to wait for the customer to finish the call she was busy with and open the door. All because she dared to ask him why he did not call and he says the phone was too busy. is this it. must my line be open 24 hours after booking a delivery through courier guy. All I can think is he wanted the parcel for himself...