Fixed.
I called Air Canada a second time. The agent was charming, thoughtful, and informative. She explained that Air Canada processes requests based on departure date. She asked if I had a moment, and she took care of it while I was on the phone with her. She was more than accommodating, and she said that the information should be linked to my Aeroplan profile for future travel. I now have a confirmation email, and I can see the SVAN indication online and in the app.