Have you tried FB Messenger? Always gotten prompt responses if your looking for general help.
But I suspect you need to get a good book and speakerphone and sit on hold for Aeroplan. I had to call a few times this week via the SE desk and the wait was under a minute so surely the main number isn’t more then half an hour? They really need to process a refund for your ticket. I have had “no shows” be forgiven and refunds issued but they certainly don’t have to (and those were I think mostly passes where they just put the credit back in). Hopefully you took a screen shot of the error when you tried to cancel?