我要打一封英文的致歉函，不知道該怎麼打?

Question

我要打一封簡單的英文道歉信函，但真的不知該從何處下手，不知有沒有人可以幫幫我。
主要內容是要告訴客戶，因為當日因為一時疏忽，而忘了把應找給客戶的錢找給他，我們真的很抱歉，並會於星期一請快遞將應找回的金額返還給他......
感謝!!!

若客戶收到該筆金額後，我該怎麼去詢問他是否已由快遞收取該筆款項呢?
謝謝哦~

Answer 1

Dear(對方名字）：
Hello! This is a letter from（打公司名）
Due to my ignorance, I forgot to turn the change back to you. We are really sorry about that! And we''ll give the money back to you by express on Monday.
Thank you very much!

Best regards,
（打你的名字）
（最後打上日期及公司資料）

如要詢問他是否已由快遞收取該筆款項可說：Did you receive the money we sent to you by express?
或者可在信後打：ps. If you reive the money, please let us know. Thank you!

Answer 2

有關忘了找錢的抱歉信:
Dear xxx,
I am so sorry that we have forgotten to give you the changes from the order on the day you visited. We will send the changes to you the first thing on Monday with Fedex or UPS. Sorry for the mistake.

問他有沒有收到錢的信:
Dear xxx,

Have you got the money I sent to you on Monday? We sent it with Fedex ( or UPS). The tracking number is ........ I have checked on the Internet about the delivery status and learned that you should be able to get it in these couple days. If you have not received the monday in these couple days, please let me know.

Regards,

XXXX

Answer 3

Dear sir,(Dear Mr. XXXX,)
We are terribly sorry to inform you that due to our negligence, we forgot to give you the change we should give on April 10/Friday.
We will send the money back to you through express delivery on next Monday.
Sincerely yours,

Dear sir,(Dear Mr. XXXX,)
We had sent the money to you through express delivery on Monday.
If you have received, please let us know by E-mail/letter/phone.
Your kind reply will be highly appreciated.
Cordially yours,

Dear sir,(Dear Mr. XXXX,)
We are wondering if you had received the money we sent back through express delivery.
We await with thanks to your soonest reply.
Truly yours,

Answer 4

Because same day because neglects for a while, but forgot to be
supposed to look for customer Qian Chaokei he, we really very much was
sorry that, and could the amount which please express will be supposed
to retrieve to Monday return for him..... Thanks! ! !
補充的問題我就不知ㄌ