Currently in JFK as part of a return back to Europe on LAX-JFK-LHR-MAD. Flight JFK-LHR on BA metal is delayed and BA have emailed to say it is likely rebooking for the last leg will be needed and they will do it automatically if so.

No interest in going back to Madrid but would like a refund for the sector if possible. Booked via AA.com is there any need to do anything before going through immigration/leaving the airport? I assume I’d speak to AA by phone rather than BA in anyway?

Edit BA staff have said something about no refund or changes due to it being a restricted ticket..

Thanks!