beta
under the assumption that the phone rings approximately 5 times with each interval being 3 seconds, each call would total to be 15 seconds long.
without the addition of redialing the number and other human errors such as unregistered taps, time delays, or missed buttons, they have spent a total of ~1.93 hours (115.75 minutes or 6945 seconds) waiting for the automatic voicemail message
in conclusion, this guy spent at least 2 hours doing nothing but calling or worse, called on intervals throughout the day even whilst busy making the total time count bigger