They are the regulatory body that deals with that sort of stuff. I know they've smacked BellNexxia around a few times for shenanigans... and their word is literally law in the business.

So far, they've done a pretty good job. Was talking to a reactionary about gov reg up here not too long ago (family member) and I pointed out to him that without the CRTC forcing the telco's to split off wire provision from ISP service and offer it to all (including themselves) at identical rates, my cousin's ISP would have folded years ago as Bell leveraged their monopoly on the last mile to shut out anyone else out of broadband access over their wire.

I just wish they would take a similar approach to the cable companies, but they don't have monopoly status in television provision like Bell does in phone provision, so they get treated differently.