2008 early Macbook Pro's graphics processor failed, but the apple store refused to repair it for free

I have a 2008 early Macbook Pro, and the graphics processor failed recently. No video on the computer screen (or external display) even though the computer is on. Today I took my laptop to a Apple Retail Store, and they checked for me. They told me that the graphics processor was dead, but they refused to repair it for free. They said their program only covers computer produced between May 2007 and September 2008, my computer was not produced in that period. But if you check this page: http://support.apple.com/kb/TS2377?viewlocale=en_US what they said is " If the NVIDIA graphics processor in your MacBook Pro has failed, or fails within four years of the original date of purchase, a repair will be done free of charge, even if your MacBook Pro is out of warranty." They never say that they only repair computer produced in a certain period for free. Obviously my laptop's graphics processor failed because of nvidia's design issue. It's not the customer's fault. But they refused to do what they promised. What should I do?