So what company or service are they representing?

Call almost every day.  I am no longer polite with them and they still call.The do not call registry is a joke.  Still get all sorts of unwanted calls.

They have called so many times, Air Duct Cleaning Service...each time I tell them I am on the do not call list and they hang up.  UGH!!!

why they call us too many time

These guys are trying to get around Canada's Do Not Call List.  Start making a list and report them - would be great to get a landmark case decided against these guys.

When these people call about cleaning my ducts I reply that we don't have ducks or geese for that matter.  Usually gets a pause and silence from them.  I will have to try the quacking next time that someone suggested in a previous note.  I thought that was cute.