Big O tires Not honor warranty cortez colorado

I bought some tires from Big O tire company.  I was told to have 1 tie rod fixed.  When I found out that I needed a inner tie rod for the vehicle I refused their service and took it to my mechanic which was cheaper than using the tire shop.  I drove my truck after having the both sides of tie rods upper and lower replaced along with a alignment after the work was done.  I took my vehicle on a road trip in which the rear tires wore down in 2 weeks.  Which I say that the tires were cheaply made. 

I got back home and took the tires to the store in Cortez in which the manager told me that he refuses to honor the warranty since I did not have the work done in the tire shop.  The manager thinks that I did not have the stuff fixed but refused to have it checked to see if I did have the items fixed because I refuse to pay the price that they wanted to charge to have them done.  Pulling a heavy trailer needs tires that are not soft, which I found out prior to this purchase.