You might want to provide a bit more info, but what from you have provided I can think of two possibilities. Are your throws set too high on the elevators so that when you pull back on the stick shes snapping? There has been much posted on this subject with this airplane specifically and she will definitely snap when you pull back on the elevator if the throws are set too high. One way to test this is to get her up high and then at about half throttle pull back on the elevator all the way. If she snaps out of the loop then you have too much elevator throw. I would first want to make sure all the electronics are fine before flying it again.

Did you do a good range check to make sure your aren't getting any interference? Might want to turn on the switch and start the motor. Set the throttle to the same rpm where you think you are encountering the problem and then pull back the elevator to try and recreate the problem on the ground. Just my 2 cents. I had this airplane myself and I'm pretty familiar with how it flies. On one of these models I had a cracked ceramic filter in the Rx - per post crash testing from Hobby Services. I took off and then she went hard to the right and then straight up. I had no response at the controls and she went in.