Duct Cleaning Co. Called my cell and said I used their service 5 years ago. I told the last 2 callers I have moved since then and to take me off their list. They call from different numbers. I don't believe they are from the same company. It is so annoying even though I've registered with the National Do Not Call Registry. That doesn't work as no one pays attention and th e CRTC doesn't enforce it.