Your Tranny is fine. My did the same thing from about 1200km to 3000km... then it fixed itself. So that is not an issue. Toyota Canada told me to use the Manual Mode while downshifting for a while until the issue is resolved if it bothers you that much. But I wouldn't think it is the end of the world. Your Car is under warranty for a while. Just ride it out, and manually teach your car when to downshift properly. There is no need to go to court, your car is fine. I HAD THE EXACT SAME ISSUES, but they fixed themselves with time. I am at 8000km now and for the last 5000km my car has BEEN PERFECT...
I drive a XRS w/ Auto Tranny, built at Cambridge
So ride it out, and do the manual training of when to properly downshift for like 2000km, and see if it fixes it, and if it doesn't, then talk to your dealer.
refer to this thread for more information
New Issue When Downshifting from 2nd to 1st Gear (Automatic).
