Engine Cooling System problems of the 2013 Chevrolet Silverado 2500

On Aug 2, 2015 about 25 miles east of grand junction CO. Driving speed was about 65 mph on interstae I-70. My chevy Silverado 2500 went into a computer shut down. Being a skilled professional driver , with a class a cdl I just made it to the shoulder before truck shur down, truck and travel trailer I was towing needed to be towed to ed bozarth gm dealer. On Monday I was informed would need to pay $ 775 to determine point of failure. At the time a company called speedco was and maybe suspect as to cause. The did a oil change and fuel filter in w. Memphis ar. This service was done on July 24,2015. On July 25,2015 truck no start, speedco came out with another fuel filter. When first fuel filter taken off , there were no gaskets. However gm appears to be conceling material facts as to internal service bulletins. This bulletin as to point failer was printed Aug 3, 2015 , 5 pages . A estimate by said dealer was given to speedco and myself in the amount of $ 8,692. 02. When the fuel injection pump went , sent metal shavings though my whole system engine, fuel oil, cooling system ect. Gm has know about this problem for a long time, however failed to disclose to its customers. In my opinion to allow for warranty to expire. Once speedco was presented with service bulletin they backed down from paying. Gm had proved to speedco that gm is the problem. I have contacted gm in detrioit many times with different case numbers. One phone call I got from gm , stated the original estimated stated above was far low. When I asked how much, stated to me could not say however much higher. I'm in possession of a lot of documentation. I havn't scaned the documents yet. This truck was purchased in oct. Of 2013 for $ 56,000, bank financing. Also this truck was purchased to earn a living pulling new travel trailers. My excellent credit is on the line due to this lemom. Truck had 20k, with warranty.