Repeatedly called asking for my wife by first name  Lots of background noise like boiler room atmosphere. Scam.

Called repeatedly, often several times a day and would always ask for my father by his first name. My father always works during the days so I would tell them that he wasn't there and offered to take a message or give them his work number. They would always refuse and say they would call back later. Whenever I asked why they wanted to talk to him they would say they needed to thank him for something but wouldn't say what. They continue to call multiple times, often 5 or 6 times a day for three weeks now, and now when I answer and say "hello" repeatedly they don't even answer, and all I hear is background noise and breathing for about a minute until the call disconnects.