I bought 4 new tires about a year ago and had gotten a nail in one tire. I used PepBoys free tire repair service that came with the purchase of the tires.
They would only put in a plug (which I thought was illegal to do these days). About 6 months later, the plug started leaking. Rather than take it back to PepBoys for repair, I went to the friendly and helpful folks at Discount Tire, that also repairs flat tires for free (even if you did not buy your tires from them) and they always use a patch for the repair. Well, they said that the plug had enlarged the hole so much that it could not be repaired, plus they discovered a bulge in the sidewall and said I should take it back to PepBoys for coverage on the Road Hazard that PepBoys made me purchase when I bought the tires in order to get the rebate they were offering.
These were 75,000 mile tires and I had only put 12,000 miles on the tire (1/6 of its life). They would only credit me $36.00 on a new tire, plus I had to repurchase road hazard and pay a tire balance cost.
So my cost came to what the original price was on the tire when I purchased it! I will never use PepBoys for ANYTHING again.