Sears Auto lacks of sevice quality

I've always regarded Sears as a quality store with excellent products and knowledgeable employees. However, in April 2009, I went for a service and I was told that I needed to replace four tires as they were claimed nonservicable. I realized that I replaced all the tires 3.5 years ago and tires should still be within time and mileage warranty. They said tires were worn unevenly due to misalignment. So they could not be covered under warranty. I then asked why I had been to Sears for oil change and tire rotation service regularly and every time some kind of points inspection was covered, why no one told me that I needed to do alignment. The manager there insisted that tires were worn unevenly.

The next day I took the car to Sears Auto in Carson. The technician checked the car and said tires were evenly worn and wrote this statement on paper. The two sears auto centers had complete different opinions on the same set of tires on the car.

So I complained to Sears, but they insisted that tires worn unevenly due to misalignment and finally they agreed to give me 29% credit of tire price (based on rest of mileage unused toward warranty) IF I replace all the tires in Sears again, but they never addressed my question why their services were inconsistent. Where is the quality of auto service?

I paid good money on the tire replacement and all services there before, I would rather avoid use Sears again for any kind of service anymore because I do not trust their service standard anymore.