Sorry to hear about what happened. You most likely won't get IDB compensation unless the flight you were denied boarding was oversold.

I would still file a complaint with the CTA. What Air Canada did was illegal and should be investigated . It would be even worse if your flight was oversold and the agent in Toronto intentionally refused to help you in an effort to deal with the oversold situation.

You should contact customer service. As they were at fault they might throw some miles or a voucher your way but they will do whatever they will weasel their way out if paying IDB, even after admitting fault. Had this happened in Europe they would have been liable. The law here needs to be changed.