Looks like your VIN is included in the range. That's good. Your injectors are covered for 7/200K.

The pump is an integral component of the engine, and therefore, covered by the 5/100K warranty. Your dealer should have covered it. It isn't too late. You can be reimbursed for all costs. Now, if the pump replacement didn't repair the original complaint, they should be reimbursing you anyway. My guess is they replaced a good pump. FPR's (fuel pressure regulator) can fail, but the pumps rarely do. If it is a pressure problem, the injector failure can cause the same codes as a failed pump.

You need to insist your dealer at least reimburse you for the pump replacement. That's a huge chunk o' change that you should have never been charged. If your dealer won't play nice, find another one that will. They can help get your truck fixed rignt and get your money back. If the dealer that did the pump replacement has a bad reputation among other dealers in the area, the other dealers would love to take them down. It only takes one bad dealer to screw it up for the rest, and they will do what they can to remedy that. If you don't get immediate response from that dealer, initiate a formal complaint with GM customer service. You can either do this by phone, or through an uninvolved dealer that is willing to help you.

Good luck! And keep us informed on your progress.