An adjustment letteris a letter that corrects a mistake. When company has made a mistake, it is important to acknowledge it, correct it, apologize for any inconvenience.
Before you write the letter, make sure you have all the information about the situation. If necessary, contact other people in your company. Ask them if they have anything to add. In some cases, you may to offer something as an apology: a coupon, a discount, or a small gift.
Vocabulary:
We apologize for the error.
A revised .....................................is enclosed.
Again, we regret the error and apologize for any inconvenience.
We look forward to serving you in the future.
You will receive a refund for your shipping costs.
I am sorry that the item you ordered was not in stock.