SEARS PLASAM TV

I purchased a 42" Plasma TV from Sears and baught the service warrenty (extended) and now there is a problem with the TV when i took it out of the box. I went to return it for a new one and they wanna service it with the extended warrenty and i should just receive a new one under the 30 day return policy. i AM SO MAD AND DONT KN OW WHO TO CONTACT THE MANAGER OF THE STORE WONT EVEN HELP ME. I will never shop there again and will tell others the same.