Transmission Fluid Leaking problems of the 2009 Nissan Frontier

Transmission needs to be rebuilt due to manufacturing defect after only 64,000 miles. Radiator fluid has leaked into the transmission oil which is a manufacturer defect. Quoted $4200 in repairs-they will need to re-manuacture the transmission and replace the at valve. I reached out to Nissan for assistance in the matter since I am just outside of the 5 yr 75,000 mile extended warranty (5 months over 5 yrs). They advised this is not something they will help with. When I asked if this is a normal occurrence for Nissan transmissions to need to be repaired at 64k the regional customer service manager simply stated he is not a mechanic. At 40mph, the vehicle jumped out of gear while driving. I had no power and needed to pull over. This put my property and well being in severe danger. Luckily I was able to get over without incident, but this may not be the case for someone else. This is clearly a manufacturing flaw and needs to be handled responsibly by Nissan. Extend my warranty and fix the transmission free of charge.