Special thanks to Rigo Cortes for the following info:
Mortal Kombat Season Pass Update
Thank you for purchasing the Mortal Kombat Season Pass on Xbox 360. Once the Season Pass has been purchased, you must access all downloadable content using the menus within the Mortal Kombat game. WARNING: If you access DLC through the Xbox Marketplace after purchasing the Season Pass and not through the steps below, Microsoft will charge you full price for that item.
To properly access DLC for those who purchased the Season Pass, please follow the directions below:
1. From the main menu, select EXTRAS 2. In the EXTRAS menu, select DOWNLOADABLE CONTENT 3. Scroll through the menu to find the specific content you are looking for 4. Follow the on-screen prompts to download your content
If you experience any problems with downloadable content or the Season Pass, please contact WB Games Customer Service Department by calling (410) 568-3680 or via email at support@wbgames.com.