I'm familiar with the expression but if an American said that to me, I'd probably think it meant "rethink what you just said".
I'm familiar with the expression but if an American said that to me, I'd probably think it meant "rethink what you just said".
It depends a lot on their tone. Most of the time I've heard it, it's a quick "begpardon?", sometimes with their ear cocked towards you.
When I see it in writing, I too for some reason picture an angry posh British man who is about to demand satisfaction.