Had AA reroute a flight which meant it was possible to cancel and get a refund. Put in for a refund which was processed within about 7 days, but was a bit less than expected. Simple question - is there was way to find out the breakdown of the refund?

Details: AA ticket on BA metal, AMS-LHR-IAD then BWI-LHR-CPH. The return was rebooked with over a 3-hour change and change of return departure airport.
Original ticket was offset by a flight credit, with an additional $1467 for the round trip. Refund of $493, so about $240 less than 0.5x$1467.