Originally Posted by
purch
well they only have to communicate the change to their own pax and then the agencies,whose responsibility it then is to inform pax who booked their tickets through said agencies.
Correct, but the agency's responsibility is to the airline, not to the passenger. Agency agreements are structured so that the travel agency is working on behalf of the airline to distribute tickets. Thus, when the travel agency fails to fulfill it's responsibility, it has breached its contract with the airline, and the airline has breached its contract with the passenger.