God's Chalice Gone

Can someone answer a question for me please. My son spent hours getting achivements including the God's Chalice. He got kicked out of the game for some unknown annoying reason. When he returned he didn't have his Gos Chalice anymore. Does anyone know why this would happen and how he can retrieve it? It breaks my heart to see him cry because he put in so much work and effort in the achivement.