my ebrake is messed up too. everything LOOKS normal (rotors, pads, cables) but they just will not hold the car on any incline. I have the cable adjusted as far as it can be adjusted.

only thing I can think of is that the inside of the rotor where the park brake sits, was turned.

that is my next project, I live in a city with lots of hills, and I'm sure my park pawl is loving me! I try to park where I do not need the park brake, or stress the pawl too much, but can't always make that happen.

yours may be due to the tow truck, not sure if it worked fine before they towed it, and now it doesn't then obviously they did something.

good luck!