Why am I still being billed for S3 Glacier?

Have you done below checks ? Also sharing user guide URL https://docs.aws.amazon.com/amazonglacier/latest/dev/deleting-vaults.html

• • Check all regions: AWS resources are region-specific. This means if you have used multiple regions, you should switch to each region in the AWS console and check for Glacier vaults in each of them.
• Check S3 Lifecycle Policies: If you’re using S3, make sure none of your S3 buckets have lifecycle policies that move data to Glacier. If they do, you could still be getting billed for the Glacier part of S3. You can find these settings in the S3 section of the AWS Management Console.
• Check AWS Backups: If you’ve used AWS Backups, it might be storing backups in Glacier. Check your AWS Backups to ensure they are not creating new archives in Glacier.
• Contact AWS Support: If you still can’t find the source of the charges, you might need to reach out to AWS support. They can look into your account and help identify where the charges are coming from.