steering shaft 03 silverado

I have a 03 Silverado and took it in for a noise in the trans I thought and they had a couple of service bulletins. They replaced the rubber at the top of the strut towers, and regreased the steering wheel shaft where it comes together around the u-joint in the shaft. It did solve the noise in the front end. Now the truck has 64k on it, and its making the same noise, but louder. Everytime that I turn the wheel or hit bumps, it sounds like a bad cv joint. I can feel it in the steering wheel. I took it back to the same dealership and they won't do anything for it. They said that they are aware of the steering shaft noise and said that gm won't do anything to it. Its not a safety issue, and that it will just do it again if they do fix it. They want to charge me a hours labor to lube the joint again. My fathers 03