Easy way for it to get bent and it actually happens more often than you know. The nut on the pivot bolt is not tightened after belt adjustment, because let's face it, that nut is a little tough to reach. So they just leave it. Vibrations work the nut off and the bolt decides to take a little trip. But alas, the bolt can only go so far. Then the belt starts to squeal so they tigheten the belt using the adjuster, which slowly pulls the alternator towards to crank pulley a little since the pivot bolt is no longer in place to keep it lined up.
Regardless of how, I have a couple is you can't get a new one.
Wiz