British Airways — Delay in Flight leading to monetary loss

Flight delay of more than 2 hours on British Airways flight number BA 0833 from Dublin- London Heathrow and BA0119 from London to Bangalore on 10th December with PNR: KQBAUN resulted in missing of connecting flight. I understand that sometimes delays are unavoidable, however, the length of the delay was unacceptable and I believe that I am entitled for a free reschedule of my return flight as it was the Airlines that caused my appointment cancellation because of which I missed my Passport renewal appointment in Indore and now have to return early as my passport is expiring early next year.