先日Aを購入したお客様からセンサーが反応しないとの連絡がありました。手持ちのセンサーと交換したところ改善したので初期不良と思います。交換してもらえますか?
I received a complaint that a sensor was not responding from a customer who bought an item A on the other day. When I replaced its sensor with the one I had, the problem was solved. I assume the problem is initial failure. Will you replace the item with a new one?