In the fall of 2015, I planned to travel from Toronto to Vancouver and back. I booked my outbound flight with WestJet, and the return flight with Air Canada, because the timing of those flights was most convenient for me. Then an unforeseen problem arose, and I had to cancel my trip. Each airline told me I could cancel my flight, pay a penalty (I thought it was $100 in each case), then apply the credit balance to another flight, so long as I used my credit within a year. Each airline, that is, except Air Canada.