Originally Posted by
abligh
Yes, theoretically, if you were involuntarily rerouted (IRROps). You need to claim Original Routing Credit (ORC). You should be awarded the difference between the TP and Avios you would have got for your original flight, and the TP and Avios you actually got for the rerouted flight. In the past this normally took 7 days or so after talking to BAEC. These days, whether you actually get them in practice and how long it takes to get them is anybody's guess.
Note this is different from the OP's issue. The OP missed the flight through their own mistake. It also needs to be a reroute (roughly) on the day (IRROps) rather than you accept a changed flight itinerary in advance as I understand it.
Originally Posted by
Tafflyer
Yes. Call BAEC and ask for original routing credit. You should get TP and Avios corresponding to your original booking.
Just to close out my side of this thread, and as reported in a similar thread: at this point BA will not credit the "missing" (ORC) Tier Points/Avios for my missed flights. They have stated that TPs/Avios are strictly for flights flown and that my flight change was voluntary. I'd argue that it wasn't voluntary given the re-route was due to BA's delayed flight etc. I claimed initially through the web form but then followed up with BAEC on the phone after they denied it. Took 2.5 weeks for the initial claim to be responded to/denied.