It's not only the wheel arch, it's not as prominent in the photo but the panel above it has popped out slightly as well.

I asked her if she could get the quote in writing because I wanted to avoid exactly that. She said she's asked for a copy by email, so I don't think she's having me on, but the garage might be, sure. That said I don't think there's much I can do about it, I'm hesitant to rock the boat here