It's disappointing when your new vehicle starts acting up, and even more so when you feel you are being ignored or just not being treated fairly by the service department. Every manufacturer has programs in place to deal with these sorts of problems, and every dealer is rated for their C.S.I., or Customer Satisfaction Index. Surveys are sent to you when you buy a new vehicle and every time you service it. Fill them out and send 'em back. It's the only way to let the manufacturer know the good dealers form the bad, and it does matter to the dealership, believe me.
High scores mean more allocation and bonus money and the dealer wants that money.
You can get satisfaction with a nagging service problem. It might be a long haul, but eventually it will be fixed, your money will be refunded or you'll get a new vehicle. Don't back down. Let them know you won't be dissuaded. We do not endorse any such activity for others or recommend it to any particular person - we simply describe our experiences and opinions.