Tire Valve problems of the 2002 Chrysler Sebring

I purchased 2 each eagle GA p205/65r15 tires for the local goodyear garage on Jan. 20, 2007. I initially wanted to purchase 2 other tires but since they didn't have those in stock, they told me they would give me these tires for the same price as the other tires. In may of 2007, I had to have both valve stems replaced on the tires and again in November of 2007 because the tires kept leaking air. I purchased the tires at with 53861 miles on the car. I currently have 74747 miles and was told Aug 15, 2008 by the same goodyear store that I needed new tires because the tread was down to 3/32. After they called corp and I complained, I was told goodyear wouldn't replace the tires until the tread was at 2/32. My tires leak air constantly and the tread wear is very apparent. I was told it was probably a suspension/non rotating tire problem. The tires were rotated every 4 months during the oil change. Nothing has been done to correct the failure since goodyear won't even think about replacing them for another month due to not enough tread wear!!.

Flat tire, leaking valve stem 15400 miles, flat tire---another leaking vale stem, 17244 miles--2 different tire involved.