I didn't know this until recently, but there is a national do-not-call list you can register your canadian phone number to through the government of Canada:
https://lnnte-dncl.gc.ca/en
Additionally, if you're already a customer with the company calling or have been within a year, they are allowed to call you; HOWEVER,
Next time a company -- like rogers for example -- incessantly calls you, ask them to add you to their internal do-not-call list, and enjoy your peace knowing that if they call you again, you can report them to the government of Canada. They face possible financial repercussions if this happens.
5 all the way