2011 tundra outside tire wearing on 2011 Toyota Tundra

my tundra has 23000 mil and had to replace my stock tires 14000 mils I was told to get a more of a square tire so I got 20" rim and now tires my alignment has never been a issue I put 9000 mils on the new tires and they are cupping and wearing on outside please help me

Asked by for the 2011 Toyota Tundra
check front end and alignment call the dealer with vin# to find out if it is still under warranty
it is under warranty and I have had my alignment checked about 5 times and no probs and the dealers in Idaho never wont to do anything