Revealing mistake: When Augustus is leaving the factory, he is wearing a brown colored glove on the hand he gnaws on. You can see the seams in the glove.
Revealing mistake: At the beginning of the song about Mike Teavee, it can be seen that the reflection of the shrunken Mike on the glossy table is not actually his reflection but rather a mirrored and flipped version of the footage.
Answer: We are never shown what happened to him but he may have gone to live with relatives or he was simply put into an orphanage.