The issue I have had with phoning in is that the BA exec team said their system could not recognise my booking reference or ticket number and therefore they could do nothing from their side to assist. The person I was speaking to also checked with their supervisor (the whole call took an hour!) and they ultimately confirmed they could not proceed any further and just suggested I submitted a claim online (which I have already done previously together with supporting docs for this flight without success). I have however now resubmitted my claim with a copy of my original AA ticket record which my travel agent has provided to me. Fingers crossed..