Sounded like it was from a phone bank.
There was no one the line at first. Then a lady picked up
the phone and said hello. I said may I ask who's calling.
She said who are you?
I said you called me.
She said well I thought I was calling a business, so that was not the proper way to answer the phone, etc.
and I hung up. I called back and got a recording for AmVets. It appears to be a marketing company who solicits for AmVets
They call several times a day, every day. They refuse to leave a message. That tells me right there this is not a legitimate business call. Besides, I am on the do not call list