A duct cleaning company. I get 3-4 calls a week from one duct cleaning company or another. The all seem to be the same place, the change their name to avoid detection by the CRTC due to the no-call registry. Here's what I did.

1.) Talk to them, try to get as much information as possible. Asking for an address of their business usually gets you a nice hang up. Try to get a phone number for their sales department.

2.) Report them on the CRTC's website: https://www.lnnte-dncl.gc.ca/plt-cmp-eng

3.) Give them a fake name.

4.) Schedule an appointment for them to come clean your ducts, make sure you are not home, or tell them to get lost.

They showed up at my house on Monday, I asked them how they liked their time being wasted and told them to get off my property and stop calling. They became extemely angry and threatened me.