2013 NISSAN CUBE Unknown Or Other Problems

I WENT OVER A SET OF RAILROAD TRACKS IN CARY, NC WHICH SEEMED PARTICULARLY CHALLENGING FOR THIS PARTICULAR VEHICLE AT, I ESTIMATE, 10-20 MPH. THE VEHICLE FELT TO US LIKE IT WAS BREAKING APART. AFTER THIS THE VEHICLE SEEMED SEVERELY MALALIGNED. I BROUGHT IT FOR AN ALIGNMENT AND THE TECHNICIAN TOLD ME THAT THERE WAS NO WAY TO ALIGN THE REAR AND THAT THE AXLE HAD BEEN BENT. SUBSEQUENTLY NISSAN HAS BEEN TELLING ME THAT THERE IS NO WAY FOR THIS DAMAGE TO HAVE OCCURRED GOING OVER TRACKS AND THAT I MUST HAVE HIT SOMETHING. I ASKED A CERTIFIED NISSAN MECHANIC ABOUT THIS AND HE ASKED IF THERE WAS ANY VISIBLE DAMAGE TO THE AXLE HOUSING (WHICH WOULD BE INDICATIVE OF THE VEHICLE HITTING SOMETHING). BOTH THE ORIGINAL ALIGNMENT TECHNICIAN, AS WELL AS ANOTHER CERTIFIED MECHANIC HAVE STATED THAT THEY SAW NO SUCH DAMAGE WHATSOEVER, WITH ONE SAYING THAT THE...