In early March I booked BOS-LHR, ATH-BOS and paid to upgrade to premium economy. I just saw that AA canceled BOS-LHR and rebooked me BOS-ORD-LHR, and the departure time changed from 7:50pm to 2:30pm. I just submitted a refund request on the website. But how do I get refunded the premium economy buy-up? I don't think it had a separate ticket number or anything.
The rebooked flights put us in regular Y, so it's clear I should get a refund of that, at any rate.