This is from an anime (Kanon ep 1, 07:58). Yuichi says:
いや お前って 変わってないよなあ
Which I understand to mean "you really haven't changed." I believe the first って is replacing は and 変わってない is short for 変わっていない.
Nayuki replies:
それで 成長してないで こと?
From the context this seems to mean "by that are you saying I haven't grown up?" I know that (verb 1)ないで(verb 2) means "do verb 2 without doing verb 1". But verb 2 seems to be elided here and I don't know what it is. I thought maybe こと is short for ことがある but that doesn't totally make sense. I would expect something more like this:
それで 成長したことがない?
Can anyone explain what's going on here?
Edit: Chocolate notes that this is probably a transcribing error in the subtitles and she probably actually said:
それって 成長してないって こと?
I'm guessing the って here is an example of って as indirect speech. But still not clear on the role of こと in this context (I'm guessing some kind of nominalizer).