Frame Rust problems of the 2002 Toyota RAV4

I have a '02 Toyota rav 4 whose k- frame, which supports the front wheels and steering mechanism, rusted completely in half, which caused me to run off the road when I braked suddenly and it cracked. The vehicle has 150k and I have always kept up the maintenance and had no idea the rust was that bad. Toyota has not responded to my complaints, even though they are covering even older tacomas and tundras because of their rusting frames. I am very frustrated and disconcerted in Toyota products ,especially since their latest ad campaign touts their longevity and dependability. Thank you for attention to this matter, I'm sure that I'm not the only Rav4 owner with this complaint.