The Disney Channel is something completely different than Disney+. It's unfortunate the person you talked to does not sound like they were aware of the difference between them.
Disney+ is available in Canada but it is not actually a channel. It's purely a streaming service. Disney has purposely only made it available on a limited number of platforms and devices. At the bottom of the main website for Disney+, it outlines what devices can access the service. None of the TV service providers have Disney+ on their normal set top boxes. The very few that have Android set top boxes that run standard apps could offer it.
The only saving grace is that "Get Back" will still be available on Disney+ after the initial release dates. Disney has not yet said when the episodes will be removed. You'll just need to ensure you have a compatible device to watch it on. Common ones include most newer game consoles, AppleTV, Chromecast / Google TV / Android TV boxes, certain Samsung, LG and Vizio smart TVs, and Amazon Fire devices. It will also work on your phone, tablet or computer.