ご連絡ありがとうございます。
この件の詳細は、前回のメールでご説明させていただきましたが、
今回の件は当店にも落ち度がありますので、
pickの不足分2picksを、あなたへ無料で追加発送させて頂くことでよろしいでしょうか?
お手数をおかけしてしまい、申し訳ありませんが、
あなたの回答をお待ちしております。
私共は、この問題を解決するためにベストを尽くします。
ご理解とご協力をお願い致します。
The details of this case was explained in the former mail,
but this time's case had been caused by our shop too,
therefore, could we make an additional shipping of the lack of 2 picks for free of charge to you?
We are sorry for this inconvenience.
We wait for your response.
We will do our best to solve this issue.
We hope your understanding and co-operation.
Regarding to the details of this issue, I've explained in the previous email for you, but there is a fault with us, too, so could you forgive me with my sending shortage 2 picks for you by free of charge?
Sorry for troubling you, but I hope to hear from you soon.
We'll do our best to solve this problem.
Thank you for your understanding and cooperation.
I explained the particulars of this matter in last email, it is also our fault in this case, so is it all right with you that I ship the lack 2 picks by free of charge?
I'm sorry to have troubled you, but I await to your reply.
We will do our best for resolve this matter.
Please understand and give us your cooperation.