2005 Chevrolet Silverado 1500 steering problems

Vehicle was sold which was believed to be an illegal california safety inspections had for three months driveshaft flew off of vehicle a week after purchasing dealer ship fix but but a driveshaft that was to short for the vehicle which was the reason for the incident second incident cause collision into brick wall because vehicle lost steering believed to be cause by safety issues dealership retired to pass off as an "as is " vehicle air bags did not deploy

Took truck in for check up said steering worn and leaking both left and right was replaced with chevy parts at chevy dealer it is now 8-22-12 now took it in to have it check before vacation and their saying the steering box leaking mileage now is 37,778 I don't understand the trouble with this part it is also very expensive.