 
You don't call to talk to a machine, so, at Wiles West a real person always answers the phone.   Even when there's no one in the office calls get forwarded to the field or living room or wherever someone might be, so that a real person will answer (at least during business hours, maybe other times too).
 
 
Of course there may be times when everyone is beyond cell service.   Signals just won't bend around or go through mountains or canyon walls.   At those times leave a message including your name, number and the best time/s to reach you and someone will call when they're back in civilization.