Log in to your customer center, go to support and enter a chat with customer service. Describe your story in detail, including the promises made by various Videotron agents, and see what the CSR says. By going through this channel, you'll have an indisputable written record. There is not much more that you can do right now, except to keep following up until you get your due but at least by documenting it you strengthen your case. Don't forget social media - these companies don't like complaints aired on social media for all to see so they will generally address it. Post your story on FB and tag Videotron (just make sure you control your language & anger or you'll erode your own credibility).