Did the bike shop actually see the bike ? Or just get a verbal description ?

This blue frame has a replaceble hanger. You can see that the bottom hole where the derailleur attaches is made of a separate piece of metal and attaches to the frame. Once aluminum gets a severe bend, it's often too fragile to bend back, and since hangers often get damaged, the replaceable hanger was invented. Now, I have fixed old Cannondale broken dropouts by rewelding in a new piece, but it's not something that is recommended or easily done.

A shop, with a hanger alignment tool MIGHT be able to bend it back well enough to make it work ...... It's worth a try, but don't be surprised if they say it broke off or got a bad crack while trying to fix it.



This steel one is non-replaceable. It's all part of the bike and cannot be replaced (maybe re-welded). Steel is stronger, so it won't bend as badly, and can better handle being bent back.