Repeated calls for weeks, often multiples per day on my land line; may ring 6 or more times. Never answered and no results in tracing the caller. Finally, I called the number while hiding my number. When the call was answered I used one of my character voices - old man - and asked, "Who, who, who's this?"  Upon a response, old man asked, "Wh - what do you do?" They assist and offer opportunities for people to work at home. "Thi, this isn't Dr. Warren's office? I think I'm hav, having a heart attack, I need help." After a few seconds I exerted a stressful sound and dropped the handset on a hard desktop. Then I picked up the phone to listen. The [***] didn't even ask if I was alright. The number has never called my cell phone(which I could block).