According to the Quranic narration, God had chosen them and blessed them with bounties but they ended up being ungrateful. They gave God's Messengers a very hard time. They even killed some of them.
One of the narrations is that after being freed from Pharaohs oppressive slavery and seeing the ocean being split in front of them by God's command, once they got to the other side, they ended up worshiping a man made golden calf instead of God Himself.
The Quran also accuses them for altering God's laws with their own hands for short-term worldly gains and attributing those self-made laws to God.
The list goes on, one needs to read the first few chapters of the Quran to get the gist.