Imagine this scenario – you book a seat on the airline of your choice, but when you reach the boarding gate, you find that you are about to board a plane operated by a different airline. And you think, “Hold on, what’s going on here ? Why wasn’t i informed?”
Such arrangements are fairly common with airlines operating code-share agreements, where bookings can be made with either one of the airlines.
During the purchase of your flight ticket, you have the right to be informed of the airline that is operating the flight, at the point of booking or as soon as deemed practicable. If the operating airline changes after you have purchased the ticket, you have the right to be informed about this as soon as possible. If you were not informed, raise the matter with the airline which sold you the ticket.