私の勘違いで混乱を招いてしまいましたこと深くお詫び申し上げます。本来メキシコからのお客様宛て送るべき文書を、誤ってあなたへ送ってしまいました。同じ商品の在庫は複数手元にありますので、日本からアメリカまで最速で届くEMSで発送致しました。日本からアメリカへは数週間もかかることはなく、通関に時間がかからなければおそらく5日程で到着するかと思います。
この度は度重なる不手際でご迷惑をおかけしたこと心よりお詫び申し上げます。なお、商品Aはミラーが破損していますのでご注意下さい。
I apologize for the trouble caused by my repeated clumsiness. Furthermore, product A's mirror is broken, so please be careful.
I apologize deeply for having caused you trouble due to my mistakes.
Also, please be careful about handling the item A with its mirror being broken.
I am really sorry for having caused you a lot of trouble due to my repetitive mistakes. And, please be advised that the mirror of item A is broken.
I sincerely apologize for causing this inconvenience because of the series of mistakes.
In addition, please be careful that the mirror with the product A is broken.
I apologize here for all the trouble caused by the series of my mistakes. Moreover, please be careful for the good A because the part of the mirror is damaged.