Business's should stop using unidentified phones.  It was mentioned below, don't answer unknown numbers.  A difficult task when the medical profession has their nurses and receptionists use their private phones to call patients.

We get calls to our cells from numbers that i.d. from places we don't know anybody and if we do answer them they at times turn out to be a doctors office or other business that is calling. 

If you deal with the public, call them with phones that identify you, be it a business, a medical facility, or an organization.

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