Automatic Transmission Torque Converter problems of the 2008 Mazda MAZDA6

I took my car to the Mazda dealership after having experienced the 'at' light come on and a jolting in shifting gears and a real " drag" when trying to accelerate. I was told that the following fault codes "'torque converter clutch pressure control solenoid intermittent" and "transmission fluid pressure sensor/switch" indicate that I need a new transmission. I called the manufacturer because I was shocked that I would need a new transmission for a 5 year old car. I only average 12,500 miles per year, have had regular maintenance, have never heard of a transmission breaking down on such a " young" car. I believe they built the car with a poor quality product and now they will not take responsibility for it. Even prior to the current mileage I had noticed that the car was jerky and "bucks" and not powerful when accelerating but I chalked it up to it being a 4 cylinder car-- prior to this vehicle I had owned 6 cylinder vehicles-- so I didn't know that perhaps these things were an indication of a failing transmission. I tried to explain to the dealership that I felt that Mazda may have a faulty/ cheap transmission and I should not be responsible for a new transmission but they would not hear me out. A transmission should not break down after only 5 years. My previous cars lasted until 120,000 -150,000 without major breakdowns. I am livid and I feel I have no recourse. I hope someone investigates this matter. What a huge let down!!! there is no " zoom zoom" in this car. What a farce!!!!! I don't know how I will pay for this. I can't be the only one complaining of this issue.