[Date]

Dear [Name of Client],

We would like to apologize for the overshipment last [Date of shipment], especially if it has caused any confusion in your side. We received your letter for the excess merchandise and we would be arranging a delivery service to pick up the merchandise.

We checked your account to make sure that we really had a mistake of sending excess merchandise and we would like to thank you as well for reporting it to us. The delivery service will picking up the excess merchandise on [Date of Pickup].

Thank you for your recent order and you can guarantee that this issue will not happen again the future.

Yours Truly,

[Name of Sender]
[Title]
[Name of Company]