Walmart cart corral hit my car. Responsible?

This was last year and i should have found out more about it before but they denied me at first so i gave up. Ok well I had my car parked in a walmart parking lot and then a huge storm came through and blew the huge metal cart corral with a cart still inside onto my car. the two openings were firmly around the front of my car and made two dents there and a bunch of line dents on the front where the cart was. They took pictures and called me back weeks later saying they denied my claim because it was owners descretion whether or not to bolt down those things and the weather wasnt their fault. Is there anything i can do? sue them? ive heard walmart almost always settles out of court bc they dont like bad publicity. What do you think?