Oil Pump problems of the 2006 Chevrolet Silverado

I bought a 2006 Chevrolet Silverado 1500 crew cab used from bill byrd kia in panama city florida on 03/02/2009 and was told the vehicle would be covered under any remaining factory warranty, was led to believe it was a 5 year/100,000 drive train warranty. Unfortunately,. I did not do my homework on that statement. The truck had 36,581 miles at time of purchase. I have driven the truck for personal use only and took very good care and had regular oil changes performed. I am now facing a motor rebuild. The engine started making some knocking/crunching sounds from the low end and I'm told the camshaft, bearings,oil pump, seals, gaskets, etc have to be replaced at an estimated cost of $3,500. I have called the Chevrolet consumer number I found for their corp office in detroit and am told by Chevrolet that this particular truck only had a 3 yr/36,000 mile warranty. So I am left paying these repairs out of pocket on a truck less than 5 years old with less than 60,000 miles. I certainly feel ripped off after financing the truck for a period of 5 years. I have no choice except to pay for the repairs since it would have no trade in value in the condition it is in.