Warranty servicing can be a very contentious process when the company uses "rules" to skew the reality to their benefit. A 40,000 mile tire, should not wear out in 6,000 miles. Especially when all 4 wheels were aligned. The front tires wore out but the rears were "like new". The "rule" was since they were purchased on a "buy 2 get 2 free" promotion. That I would be responsible to replace the defective tires by paying the full price. Not at the discounted price. No adjustment for proration. I objected and finally negotiated to pay the labor only. As someone in the retail industry, I have always approached customer service from the consumer's viewpoint. A happy customer is far more beneficial than a crusading angry one.