I Chronicles 10:13 So Saul died for his transgression which he committed against the LORD, even against the word of the LORD, which he kept not, and also for asking counsel of one that had a familiar spirit, to inquire of it; 14 And inquired not of the LORD: therefore he slew him, and turned the kingdom unto David the son of Jesse.
Satan may have rejoiced briefly but the victory wasn’t really his. God was allowing the consequences of Saul’s sin to take place in the life of Saul.
Satan does get the victory. They do get to worship their god but it is Saul who has rebelled against God and brought this on himself. So often it is we that choose to disobey. We want to blame Satan or God but we chose to do things our way instead of His way.
When you walk in your way then you will suffer the consequences of your disobedience and rebellion.