Why did Dev write a letter to Jog expressing disappointment after the Udyapan ceremony?

Dev wrote a letter to Jog because he felt that Sai Baba had failed to keep his promise to attend the Udyapan, leaving him feeling deceived and disappointed. In the letter mentioned in Chapter 40, Dev questions how Baba could have let him down, stating, "I waited with great effort, but no experience came." He was confused because he had invited Baba with love but felt the outcome was completely contrary to his expectations. Even though three uninvited guests—the Sanyasi and his companions—had come and been fed, Dev's mind was so clouded by doubt that he couldn't see this as the fulfillment of Baba's promise. He sought Jog's perspective to understand why he was left feeling this way.