Mexican Spanish has several phrases for keeping someone content without delivering.
Dar atole con el dedo, “to give atole with the finger.” Atole is a warm corn drink. BBC Mundo, citing the Diccionario de mexicanismos of the Academia Mexicana de la Lengua, glosses the phrase as engañar, to deceive.
Dar el avión, “to give the airplane,” to brush someone off.
Dar largas, to keep putting off an answer.