#1 - Arrma should take care of you with Warranty for anything that breaks. Make use of that, especially starting out if things are not 100%.
#2 - Take some time to check out the vehicle end to end. Check for loose screws, extra play in parts, gear meshes, shock fluid levels, etc, etc, etc. It's a good way to become familiar with the RC and it may help you identify some problems before they become breakages. My guess is you had some issues with the gear setup and running it caused the failure. The ESC is unfortunately a known issue, but Arrma will send you a new one and hopefully you get the updated version.