Coding endoscopic carpal tunnel release with ulnar shortening osteotomy

We coded 25390 with 29848 for a ENDOSCOPIC CARPAL TUNNEL RELEASE WITH ULNAR SHORTENING OSTEOTOMY for right carpal tunnel syndrome with ulnar impaction syndrome. The carrier denied 29848 code as included in 25390, per AAOS guidelines. I cannot find any documentation that supports this. Can anyone hlep? Thank you.