2014 Ram Promaster Steering problems

with the complete failure of turning left on able to turn left at all I was on a job about 3 miles from the house when I got into the truck to go home I was able to turn right without the power steering hut unable to turn left. Steering only would turn left about a quarter turn ,!Fortunately these were back roads and I was able to take three attempts to complete each left turn vehicle brought back to dealer for what I hoped was a warranty repair the power steering pump is leaking they quoted to replace the power steering pump however I don't trust them because they've already had two chances to repair it and have not I brought it to a third-party for repair and it has been determined the vehicle needs a power steering pump and a rack ( rack has internal damage )and pinion for a cost of $3500 I believe the damage was caused by the dealership by reinstalling the filler cap and allowing water into the steering system. The service manager at the dealer told me water damage the components in that fashion and I asked him why don't we just use water then instead of power steering fluid vehicle only has 72,000 miles on it , even know all this has occurred in less than 1000 miles it's been an ongoing problem since august 2018 until today may 2019 I quit driving the truck because I have trust issues with the steering