I think there's a misunderstanding somewhere because in Japan "do you have X" and "do you not have X" would elicit the same response in the negative case (something like "I'm sorry, we're out of stock"). There's no reason for the speaker to say "no" either way.
I think there's a misunderstanding somewhere because in Japan "do you have X" and "do you not have X" would elicit the same response in the negative case (something like "I'm sorry, we're out of stock"). There's no reason for the speaker to say "no" either way.