Who called from 6103862262

It's a Pennsylvanian number.

receiving calls on my cell, no message left.  called back and got a recording that the number is not in service

It is a Vangaurd number, the reason you can't call the number back is because they work through their own switch board.

Agree...it's coming from Vanguard but you cannot dial in.  Not their sales dept; my call was from an internal dept. we work with, so was legit.
in my case.

Received a call from a woman at this number on Friday, 10/5, approximately 9am. I have no connection with Vanguard and did not know who she was, but she was rude, disrespectful and on the verge of using profanity towards me.  She was yelling at me, and I had no idea who she was so I hung up.