Why did Damodar Dev feel that Sai Baba had deceived him regarding the Udyapan ceremony?

Damodar Dev felt deceived because he had lovingly invited Sai Baba to his Udyapan ceremony, and Baba had promised to come. However, during the event, Dev did not see Baba in his familiar form and concluded He had not kept His word. As recounted in Chapter 40, Dev was so disappointed that he wrote a letter to Bapu Saheb Jog, complaining that Baba's assurance turned out to be false and that he felt let down despite his earnest waiting. He believed he had been given a false promise because he failed to recognize Baba, who attended in the guise of a Sanyasi with two other companions.