Can someone help me figure out how to determine if the refund I received was correct?

Background: I flew last Saturday on a paid business/first ticket from YYZ-DFW-SFO. While at YYZ waiting to depart, I received an alert that the YYZ-DFW flight was delayed enough to make me miss my connection. I called and rebooked, though the only flight with open seats when I called was one that left me with a 5-hour layover.

Just before departing YYZ, the gate agent announced that the DFW-SFO flight I was originally on was now also delayed, so passengers would be able to make that original flight. I requested to be placed back on that flight, but the GA told me it was now full. I checked at the lounge in DFW on arrival and a seat had opened up, but only in economy. I took it.

Today, almost a week later I received a refund from AA for $104.50. How would I calculate if that's the correct difference in fare for the DFW-SFO leg of my flight (first vs economy)? I did fly business from YYZ-DFW. Economy in DFW-SFO.

Under Canadian law you were legally entitled to be rebooked in your ticketed cabin on the nest flight that had seats available. After the fact you are entitled to a pro-rated refund between the fare you paid and the lowest economy fare on date of purchase. So if the fare difference was say $ 200 and you flew half the distance in economy you refund would be $ 100.

YYZ-DFW is 1200 miles and DFW-SFO is 1460 miles. So the economy portion was roughly 54.9% of the total distance. As I have no information on the actual fares, I can't offer more than that.

Thanks!

Is it the difference between the biz fare I paid at booking and whatever the prevailing economy fare was at the time that I booked? Or what the economy fare was when I was switched to economy an hour before my connecting flight left? Is there an easy way to see what past fares would have been? I didn�t take not of what the economy fare was when I booked.

I guess one way would be to look up a future business flight that cost roughly the same as what I paid for my flight, and then check the fair differential between the two classes, assuming it would be roughly the same.

Do you have the fare calculation breakdown from the original ticket? It's really hard to say without knowing that.

Yes, once we know this it will be significantly easier. Bonus if you have the T&C of your ticket.

What�s the best way to find all that?