Well, first came the offer of allowing one to pay the taxes for an Aeroplan reward ticket using your Aeroplan points (TOTAL RIPOFF), followed by this one:
It used to be (and I'm not sure when this changed exactly) that if you wished to change a ticket, you had to do so more than 33 days in advance. You could not cancel a ticket within that window, so it you wanted to cancel a ticket within the 33 days, you first had to pay to change your ticket date OUTSIDE the 33 day window and then pay again to cancel it. It used to be that this would put you back $90 per ticket for the change and then another $90 to cancel IF you were within the 33 day window.
At some point, they changed the rules to cancelling a ticket to TWENTY-TWO instead of 33 days, and they also allowed one to change a ticket more than 2 hours before the flight (or a same day change at the airport for $75, whether for an earlier or later flight on the same itinerary).
In some cases (short haul flights for example), not even worth changing the ticket. Better to buy a new one. If you cancel your ticket more than 2 hours in advance, there's no charge for the cancellation--your tickets will be in limbo for 1 year until you choose to use them, at which point, they'll nail you with the $100 change fee per direction. This rule seems to be gone come December 6, 2016, but in reality, cancelling a ticket for "free" and holding it for a year in limbo was eventually going to cost you when you had to rebook it anyways.
The only good news is about the change that happened at some point that allowed you to make a change more than 2 hours before your flight. I don't know when they changed THAT rule.
Here comes the NEWEST BAAAAD change:
Now, you can apply these "new" rules like before, but now you'll pay $100 PER DIRECTION, up to a maximum of $200 (in case you have a multi-city ticket--Toronto, Joberg, Tel Aviv, back to Toronto, you'll "only" pay $200, not more). Before, if you had to change a return trip ticket, and make changes on both your departure dates (leaving and coming back), you'd pay a flat fee of $90 total. If you had a one-way ticket, you'd pay the same: $90. Now, for changes on a return trip ticket that will effect both directions, you'll pay $200 (plus tax, of course).
The exception: if you have Diamond Distinction status with Aeroplan, which you attain if you accumulate 100K Aeroplan points in one year, through flights and Aeroplan credit card purchases (not even the CIBC Aeroplan card gives you Aeroplan Welcome Bonus points that count towards Distinction status--they were the last ones to do so--ended in March of 2016, unofficially).
With Diamond status, changes two hours prior to departure are still $75 (instead of $100) and refunds more than 22 days in advance are only $30 online, and $100 if you're crazy enough to do it with an Aeroplan agent over the phone. So, if your flight is in 3 hours, and you wish to CANCEL, first you pay $75 PER DIRECTION to change it outside the twenty-two day window, then $30 to get a refund (step two). For a non-diamond status member, it'll be $100 per direction per ticket (max $200), and then another $150 per ticket (regardless of whether it's one-way or return)--costing you on a return ticket $350 to get the points back in your account. YIKES!!
Avios still will only charge you the taxes if you buy you need a refund or cancellation more than 24 hours in advance--and if they changed the time of your flight and you point out how inconvenient that time change is, they will give you a refund at no cost. If they won't, HUCA (hang up and call again) and get a new agent who may be more susceptible to your charming way! ;)