God doesn't make mistakes so he can't repent. Rather he gave us free will which means the power to be against his will. So when God made Saul king he appointed him to be the king he wanted but he refused using the power of his free will. All of us have free will to do whatever we want in life. So he kept his word and let us do what we want. Just sitting there and watching. We are God's children so he cares for us. He doesn't want his children to be miserable as any father does so but he can't do anything to change our will. Because he has done his part, He paved the way for righteousness. It's our part to walk through the road. God does not intervene unless we asked for his intervention. In the scripture it says many things that seems to be contradicting itself but if you actually read it carefully that is with pure intentions of knowing what it really says it really doesn't.