They have called me every day this week between 3:50 and 4:05 p.m.   Same thing, when we pick up there's dead air.    I call back and get a recording that it's going to voice mail then the voice mail is set up to say it's full.

I, too will find their company information and report them.  I am also on the Do Not Call list, it has stopped about 95% of the scammers but these guys somehow get through.

What do they possibly get out of calling and saying nothing?  They certainly don't drum up business???

These "Duct Cleaners" have been calling me every couple of days for several weeks. I started out very calm and polite. Told them my ducts were just cleaned - they hung up. Told them Asked to be taken off of their call list - they hung up. I'm sure the stories are all the same. Decided to tell them that I am busy at the moment but would like to call them back to discuss - asking them for a company name and phone number - which of course they won't give... they would prefer to call back. They told me the name of the company is "Duct Cleaning Company". haha. Now they swear at me. Good grief.The hang ups were annoying... the filthy language unacceptable. Great business model. I urge everyone to keep them on the line for a few minutes.. ask them what the name of the company is. Ask about pricing... get them to go into detail. Eventually numbers will be cleared from their list.

Keep track of all the numbers you are getting called from - make a list and then contact the Police and the Governments' DNCR - and report them.  It may be it is the same people calling - but using different numbers.  They are not unlike the computer hackers - but if you don't know who is calling you from the number if you have call display - don't answer it.  Make note as above.

Just launch a complaint at https://www.lnnte-dncl.gc.ca/plt-cmp-eng if you're registered with the National Do Not Call List.

So what company or service are they representing?