Did you use the magic phrase: “I need to issue a chargeback. They charged my card for services not rendered. I called their number to contest it and they did not issue a refund.”
That (or “they charged my card but did not send the product”) has worked 100% of the time for me. I’ve never provided documentation beyond that.
Chase has a strong financial incentive to issue the chargeback (Air Canada ends up paying Chase a fine), and it’s no sweat off Chase’s back if Air Canada sues you.
Card issuers have no incentive to investigate further, and (in my experience) never ask for further documentation.