Sounds to me like he put electric bass strings on it, switched to heavy gauge, or doesn't know how to tune it
Sounds like he bought it without knowing the ins & outs of an ABG, dicked around with it (as oniman addresses), and damaged the bridge, nut, and possibly the bracing and other glued joints & surfaces which remain undiscovered. IOW, he could very well own $350 worth of firewood. Given this consideration, you don't want it back. It's possible the cost of repair at this point may very well outweigh the instrument's value.
Riis
or the strings lay flat