To update you on my last post, I did indeed call Telus to find out why I was still being charged for the TV service when I had already cancelled it. The call centre dude looked up my account and quickly discovered that Telus had screwed up another thing with my service. He apologized and instantly credited my account with bogus charges. I thanked him for that but I told him the whole process of cancelling my TV service was a horrendous experience. Having to call tech support twice and then finding out I was being overcharged was unacceptable. He agreed and offered me a free month worth of service. I probably could have squeezed more out of him but I took his offer.
I would have preferred that Telus just done everything right in the first place but at least I received some manner of compensation for my trouble.