Cooper Tires cooper tire and rubber company Terrible Treadlife; Terrible Warranty lima, Ohio

I bought 4 new Cooper Discoverer CTS tire for my Jeep Grand Cherokee in 09/09, my previous tires (Goodyear Wrangler's) last about 5000 miles past their treadlife of 45000.  The Cooper's as of 01/13 need all 4 replaced with only 25000 miles on them with an aligment and regular rotations, i still only got 36% of the treadlife out of them (70000 miles warranty). i have contacted cooper twice and a cooper dealer to basically be told that they can not help me unless i purchase brand new tires and send them back with proof of the rotations and purchase receipt which i have.  They told me that because one of my tire rotations was 1000 miles past their recommended interval that they probably would deny my warranty and not give me anything.  Wow, a well maintained in alignment vehicle with even wear across the tread is being denied warranty when it only last 35% of their warranty period.  needless to say, i will never buy cooper tires again, and will work hard to ensure others never by Cooper again.