I am sorry to hear about the issues you have been having with your Redcat. Can I ask what the original servo was doing; no movement, broken gear, slow response ect?? As far as the spur gear goes I would assume that the gear mesh was off and caused the gear to strip. All you can do is work through the issues one by one, you have the servo taken care of now you just need a new spur and to set the gear mesh correctly. I hope they will take care of you and get you up and running soon.

Good luck,

-Derek