Who called from 2022479799

We keep getting calls from this number. No one is there and when I call it back it is an invalid number.

This is a medical office billing / collection company

I placed a few test calls from my home Vonage line to our new phone system for work.  The next day, when I checked the reports, it showed that I was calling from 202-247-9799 (not even close to my real Vonage phone #).  Not sure why Vonage would be passing this number as my caller ID, but that's what seems to be happening.  My guess is that if you see this # on your caller ID, must be a friend or relative calling from a Vonage line (or from another non-traditional phone service, perhaps).