Aeroplan Terms and Conditions:

Effective December 6, 2016, changes to unused flight rewards (i.e. flight date(s), flight time(s), class of service, routing and/or itinerary) may be made up to a minimum of two hours prior to departure. A fee of C$100.00 plus taxes per direction, per ticket will apply. This fee is non-refundable.

and

Effective December 6, 2016, unused and valid flight rewards may be refunded, along with any applicable Taxes, Fees and Surcharges associated with such flight rewards, in the original form of payment made by the Aeroplan Member at the time such flight reward bookings were made, up to 22 days before the scheduled date of departure. A C$150.00 fee plus taxes per ticket will apply. This fee is non-refundable.