If a professional receptionist, working as the public face for one of the 439 most powerful people in the world, can not answer more than 150 phone calls during a shift, then there is a serious problem in her office.  I have tried countless times over the past few days to call her office, and have never gotten through to anything but a non-descript voicemail - despite using the same number I call many times each year for a variety of constituent messages.  
Methinks that the good senator's public phone numbers are set on do not disturb so as to provide plausable deniability regarding her constituent's opinions.
For the record, I know of many others who have had the same problem, and none of them are calling to encourage the Senator to kick people off of their Affordable care Act insurance or to support the nomination of a woman as Education secretary who has never interacted with the Public School system in her life!