Spare Keys not working and Car Dealer not willing to assist

We bought a Hyundai from this place and the spare keys are not working and this in a six months period when I noticed this. So should they not give me keys that are working at the price of the car that we paid for they can surely assist me in getting the keys checked or fixed. This is very bad service from the sales person Steven Lee and the manager of that dealer ship I just feel they can do the extra mile for the clients and keep clients that way and referrals