I’m going on memory here, but I believe it is perfectly legal in Ontario. I still get recorded calls from an auto dealership, reminding me that a car I no longer own is due for servicing. I just hang up, and that kills the call.
However, I believe what changed years ago was that the calling organization had to break the connection (as happens with the auto dealer that calls me) if you hung up. Taped calls before this regulation was made used to drone on with their spiels even though you hung up, thus preventing you from using your phone until they had finished. And sometimes, they would go on for ages. I once had to make an emergency call and ended up using a pay phone on the street outside because my phone was blocked by an incoming recorded call that wouldn’t break the connection.
Sorry I don’t have a cite, but I did follow this story closely when it was happening, which would have been the late 1980s or early 90s. This is what I believe happened, but perhaps somebody else has a cite for you.