Do I call the repair service or tow service first?

Shaun,

Are you sure it's the transmission and not the transfer case? If it's the transfer case there is a small plastic clip that holds the cable to the case and they are known to break easily if forced. Not expensive to fix, but not easy to access either, especially when on the road. Any Jeep dealership should be able to repair this quickly for you. Hope this helps.

John