Apparently "Window Butler" an Ottawa (?) based franchise of some US company cleaning windows.
                 

" www.windowbutler.ca/
           Ottawa, Ontario, Canada
                 Call Us Today: 613-321-4829
          Window Butler is Ottawa's window cleaning solution. We service residential and commercial clients.         We are easy to work with and easy to contact. Take a look ...

I have asked to be removed from their call list twice and that has not happend.  They call 2-4 times a week and if we pick it up there is no one there.  Their website says they are easy to work with and have a "live voice" between 8 am and 8 pm....

This type of non-delivery suggests getting windows washed by them may be risky as they do not deliver what they say.

They have been calling my business #  2x's a day for weeks.
No message.  I have called and asked the message machine to be taken off their calling list.
No luck.

613-321-4829 keep calling and no message left. If you pick up the phone and no one would speak. Annoying......

they have called a few times, despite my being on the no-call list. I haven't picked up.

Same here, reported to CRTC since we're on National DNCL and we have no business relationship with them at all.  I've suggest everyone to do the same since they're clearly ignoring CRTC regulation and people's privacy.