Who called from 4028840000

Called; hung up

This number called my business line.

No one there.

Just called my office phone. Nobody was there and the line hung up.

usually this number calls this office and hangs up, BUT today, they threatened us, who are these people/person?
why doesnt the phone company cut this line off, threatening people is AGAINST THE LAW!!!!!!!!!!!
HEY JERKS REMOVE OUR LINE FROM YOUR LIST, STOP CALLING THIS OFFICE, ESPECIALLY NOW!!!!!

I got a call from this number this morning.  I answered and they hung up.  I called back and got a message that this number is no longer in service.