My steering wheel did the same thing at the 12 position. The first dealership I took it to pulled the same thing with me and said it was my fault and my wedding ring was "nicking" the leather. Now.. like you I was under warranty and felt it should be covered because I know it wasn't my fault. I called another dealership that has seen this before and had NO problem replacing the wheel under warranty. They claimed it's from the heated steering wheel causing the leather to delaminate from the steering wheel causing the issue. Dodge had no problems replacing.
Fairfield Dodge In Muncy Pa, Chip is the service manager. Maybe he can shed some light on the topic on how to get it covered at your dealership.
Current 2013 Dodge Charger SRT8, Corsa Extreme exhaust, 20% window tint, AEM drop in filter