Acouple of questions come to mind:

1. You assembled it by the book. That's good, but you still need to bring some experience to bear. For example, you mounted the servos in the rear. I have this plane and my servos are mounted forward in the cabin area. The reason mine are mounted inside the cabin is that, after installing the engine, I "trial balanced" the plane by hanging the tail servos in the general vicinity of the rear install positions. Humongus tail heaviness! So, rather than add a bunch of weight, I moved the servos forward so my plane balances where I want it to without any added weight. Don't blame the mfg/distr.

2. You had it balanced tail heavy and still chose to fly it? Maybe the problem was not your flying (piloting) but you are responsible for putting an out of balance plane in the air. Probably not many (if any) pilots could have successfully flown it.

Chalk it up to an expensive lesson learned.

Good luck with your new plane.