what they do to test the frame is hit it with a hammer and if it brakes through the frame its recalled so there is almost nothning holding it togeather. I have heard the only way they fix it is replace the frame and rear suspension, never hear any thing about giving you a check for 150% of kbb so i would go and talk to a manager at that shop and if that dosent get you any where call a diffrent toyota dealership and explan what is going on and that the other shop is not fixxing there recall.
If they dont replace your frame, dont yell at them and just tell them you are disspleased with there costomer service.
you could also send a email and letter to toyota corperation and say what is going on and the why you want to keep the truck you have now
good luck and hope it works out for you