I'm in exactly the same situation. Had a F ticket for myself and husband to JNB using AA codeshare flights on BA. However, due to the impending strike of security staff at LHR cancelled my flights after checking that they were refundable (less $400 each in my case). Told the refund would appear on my cc within 5 days. Now, no refund but a 'credit for another flight' for each of us to be used within a year. How can I escalate this or how long should I be patient and hope my cc gets recredited (cc is Citibank AA).