ive had that happen with UPS,, i know people that work for UPS in my area,, usually when that happens its because your stop was added to the drivers route and it causes them to go out of their way so they just say no answer. so when it goes back to the station to get rerouted the next day, its usually worked into the route.. not all drivers do this,, not always lazy ones either, usually vested drivers who know how their system works and uses it to their advantage. even if they get the package the next day, it fits right into the route and no loss of time ect.