I finally got back at Air Duct Cleaning Services!  Here's how to DESTROY them!  Agree to their service!  Then, give them a false address!  They will drive around endlessly looking for the place and never find it.  It wastes their time and money.  If they call you back, deny everything.  It's not like they will get any answers or a recording of your agreement from the fly-by-night Pakistan call center.  They called me back.  I said I didn't know what they were talking about and they hung up.  If everyone does this we can drive these idiots out of business.