Transmission Failure problems of the 2008 Toyota Avalon

Cannot express my complete and utter disgust with my recent experience and overall experience since buying my 2008 Toyota Avalon. I expected "quality from the product" as the Toyota website states. . However, since I have had this vehicle the 300 dollar a piece drivers side head light blew out along with both high beam lights. Here is my current issue. My area recently went through a terrible winter blizzard. During this snow storm, driving conditions were terrible. We were all trapped in the house for days on end. Imagine my surprise when I found out my wheels are no longer spinning and my 2008 Toyota would not move forward or backwards. I had to have the car towed to a dealership only to be told that the transmission must be replaced on this vehicle with only 48000 miles on it. The comprehensive warranty that should take care of this will not suffice as the dealerships service department stated. According to a computer read out, outside influences made the transmission fail. Could that mean snow? does Toyota provide anything that says transmission will fail if driven on snow. . . . I am utterly disgusted with this situation and currently without a vehicle. I plan on campaigning very loudly against Toyota and broadcasting this deplorable situation if this issue is not resolved in a way that does not mean me buying a new transmission for a 2008 Avalon.