This fine print is not even all that fine, and certainly not "unspoken". There may have been crossed wires with the OP thinking the transaction was an up-fare and the agent quoting and selling a LMU.

I understand the disappointment, but this resembles the other recent post of someone doing a mileage run in a non-accruing booking class. The intention was clear but what you want, and what you tell someone you want, doesn't change the attributes of what a thing actually is. Better to check the rules before spending the money than afterwards. A refresher on the program would help many of these folks. For instance, OP refers to wanting "Aeroplan" but it seems the issue is really with respect to Altitude Qualifying Miles (not Aeroplan miles).

On the bright side, I presume OP had a better seat than originally booked.