I think they're casing homes to rob them. Exact same thing happened to me, they hung up when I asked for their phone number. They called and offered to come into my home to clean furnace vents, clean clothes dryer vent and A-C for $59. I told them I might want to use them, so to give me contact info - and they hung up. I also am on the do not call list.
Received a call from 314-492-5898 - Air Duct Cleaning Service, ducts, dryer vent. I listed to the spill and pressed 1 for more information person (female) came on the line. As me if I would like to hear more about the Air Duct Service and I ask for address and they hung up.
I keep getting annoying calls from this company. Once, I pressed 1 to talk to a human. Asked them if they understood I was on the Do Not Call List. The weasels hung up but still keep calling.
My advice. Talk to them. Tell them you're interested in their $59 air duct cleaning and make an appointment. When they come out, beat the crap out of them with piece of lead pipe and leave them for dead.