Why did Dev feel that Sai Baba had deceived him regarding the Udyapan ceremony, even though he had served three uninvited guests?

Dev's confusion and feeling of being deceived stemmed from a few factors, as detailed in Chapter 40. He failed to recognize Baba in the guise of the Sanyasi because this same person had previously visited him to collect funds for cow protection, a completely separate matter. This prior encounter made Dev think the Sanyasi was just a guest who came for a meal. Dev himself admitted that he forgot to pay attention to Baba's specific words: 'When I come for the meal, two others will come with me.' This lapse in memory, combined with the Sanyasi's previous visit, created a 'veil of Maya' and led him to wrongly conclude that Baba had broken His promise.