Hail damage caused by branch negligence

My car was sent into renew it for repairs after I had an accident , my car was kept for over a month with continuous delays. Once my car was eventually collected Renew it failed to inform me they had left my vehicle out and I had extensive hail damage. On speaking with the service advisor they apologized and said my car was left off the list. Not only was the service during the repair awful the manner in which they have dealt with the damage caused by them is even worse .One can only question the integrity of such businesses that go out their way to deceive clients and provide awful service.