I'm very unhappy with Nissan service department. I...

I'm very unhappy with Nissan service department. I have a warranty on my car and whenever I complain about a issue on my car they can never find the problem.They seem to find everything wrong when I have to come out of pocket. I have been trying to talk to the manager for the last 3 days and no luck. I finally picked up my car after service and was missing a hubcap. I'm very displeased with there service and no one there seems to care and I will no longer go back there for service a waste of time.