1 Samuel 15:35
And Samuel came no more to see Saul until the day of his death: nevertheless Samuel mourned for Saul: and the LORD repented that he had made Saul king over Israel. And Samuel came no more to see Saul until the day of his death: nevertheless Samuel mourned for Saul: and the LORD repented that he had made Saul king over Israel.
God gave Saul another opportunity to prove his fidelity through obedience by commanding him to destroy the Amalekites. That command carried out a sentence long before pronounced upon them because they had attacked Israel in the wilderness, defied God, and given themselves to idolatry. Its execution had been delayed for four hundred years, yet they had not turned from their sins and still stood as a threat to God's people and to His worship.
Saul rejected the word of the Lord and chose his own will, denying wrongdoing and excusing himself rather than confessing his sin. The Lord therefore rejected him as king and left him to follow the judgment he had chosen instead of obeying. He could no longer be employed to carry out God's purposes.
The Lord no longer communicated with Saul nor instructed him through Samuel. Samuel therefore came no more to Saul with directions from God. Samuel was sent instead to anoint David, whom God had chosen to rule in Saul's place.