Faulty nVidia 8400 Graphics Card - Dell Refusing to Replace

I also have an Inspiron 1420 with a nVidia 8400GS chip. My computers graphics card started having problems around Nov 8th, 2008, a little over a year after I purchased it . We called Dell and the representative told us that the nVidia 8400GS chips were faulty, that Dell had extended the warranty on our computer for 1 year, and that they would replace our graphics card for free. I was out of the country at the time so I decided to wait until I returned to the U.S.A knowing I would be back in America before the warranty expired. Fast forward until today, August 5th, 2009. I am now in the United Sates and I checked my warranty status on Dell.com yesterday. As of yesterday, Dell.com said that my warranty expired on August 29th, 2009 (just to be safe I printed off the warranty status information from Dell.com). Also, I just received an offer in the mail which states that my computer's warranty will expire on August 29th, 2009 and wants me to renew.  I called Dell TODAY and they told me that MY WARRANTY EXPIRED LAST YEAR (In August, 2008) AND THAT MY COMPUTER'S GRAPHICS CARD IS NOT FAULTY AND THEY WOULD NOT REPLACE IT. The Dell representative told me that the warranty renewal letter I received was quote, "was an accident."  When I pointed out that I had checked my warranty status on Dell.com the day before and it and it also confirmed that my warranty expired on August 29th, 2009 the representative asked me to "check it now." So, I went online to Dell.com again, checked my warranty status, and GUESS WHAT? It now says my warranty expired LAST YEAR...  After I rechecked my warranty status online the Dell Representative said  that my only options were to buy another warranty, or buy a new nVidia 8400GS graphics card from them which, he claimed yet again, is not faulty.

What on earth is going on? Does Dell just delete people's warranties when it's convenient for them?

TO SUMMARIZE -  I spoke with Dell representative last November who told me that my warranty expired in August of 2009, AND I have two pieces of paper claiming that my warranty expires on August 29th, 2009 and yet Dell is still claiming that my warranty has expired. Also, last November Dell said it would replace my faulty nVidia graphics card for free and now Dell says my nVidia card is not faulty.

What can I do about this? Do I have any options? Please help me! I feel like Dell is trying to scam me. Any advice you can give would be great!