Spyglass Group.
(They call from a blocked number, but after minutes of debate I got her to give up the name of her company.)

Rude AF cold-callers. Called, tried to get passed around from person to person. and ARGUED with me when I told her to take our ENTIRE company off their call list.
I repeatedly asked her what the call was in regards to, and she insisted that it WASN'T a sales call, but rather a "financial matter" however, we don't HAVE any business with them, so yes, it WAS a sales call.

Whatever it is they're selling, we don't need it from argumentative people.

Called and asked for CFO, when asked what the call was regarding was willing to say it was a finance matter, cost center to be exact. Asked who they were and put them on hold to see if anyone was interested in taking the call. She let herself drop off my directory before even 30 seconds was up.

Of course I was told they had to follow same procedure as all cold callers. Submit in writing to the corporate mailing address please. And remove all company information from their data base. We'll have their information and no one need be repeatedly called unless or until we initiate the contact.

They spammed our entire 911 system, every number, over and over. This caused our lines to be useless until they were done with their "tests".

We tried calling back to remove our numbers, but all we could get was a voicemail.

Wouldn't work anyway, crooks don't obey laws or your wishes.