Hi japatar,
There's one statement that you made that seems very relevant here:
"....We have 4,800 miles, the rotors were just turned as they had indentations in them already...." Really, with only 4,800 miles on the odo??
This leads me to believe that one of two things may be happening; or possibly both.
1) Someone is driving the vehical and using the brake pedal as a foot rest, or..."Riding the brake".
This would cause the brake parts e.g., brake pads, rotors, mounting pins / sleeves, and calipers, to overheat from never having a chance for the "cool down" process to take place between stops; this is a very important part of the brake systems proper operation; it may also explain why the brakes are wearing "prematurely".
If the brakes are allowed to overheat again and again, the metal parts will become fatigued (misshapen), and that alone can cause the brakes to bind or drag. From there the problem just gets worse an worse.
Also in your statement you said, "They had indentations...", indicating to me that more than one rotor was suffering from the same condition (unsure if all four wheels were involved). And...
2) Toyota installed not one, but two or more (L & R), defective brake assemblies at the factory; not likely, but possible, in which case the dealership that you took the truck to, still has yet to determine what caused the trouble in the first place; can't just keep going back to turn the rotors, but eventually must resolve the root cause of the problem.
Edited: Nearly neglected to mention that additionally, there are other systems that operate the truck's braking system such as: Downhill assist, VSC, A-Trac, etc..., that may very well be malfunctioning and responsible.
Listen japatar, Toyota may have some responsibility or obligation to you for at least part of this brake problem. I think that aside from trying to locate the core mechanical trouble, I would still be holding them accountable, if in fact there were defective parts/systems involved, So be vigilant!! Good luck,
rigtec, Cheers