Who called from 8508074590

Private caller called twice today. No message and no one on line when I answer.

I have received multiple calls, and no one ever leaves a message. My home phone rolls to my cell phone if I don't answer, so I assumed it was a creditor calling my home for someone who used to reside with me. The few times I have answered, by the time I answer there is no one on the line, and every time I call back to tell them to QUIT CALLING ME the line is busy.   I am also on a do not call list.

Does anyone know, what is ADT?

ADT does home security systems. If it was them, you'd know it, they identify themselves up front.  Politely.

It IS from ADT and they DO identify themselves.  and they call EVERY day even after being told to STOP CALLING.