[DATE, ex. Monday, March 31, 2008]

[NAME, COMPANY AND ADDRESS, ex.
Link Building
XYZ Inc.
1234 First Street
Suite 567
Anycity, Anystate  85245]

Dear [NAME, ex. Link Building],

I want you to know that we value your business greatly.  Please accept my apologies for our incorrect shipment to you on [DATE, ex. Tuesday]; [STATE WHAT YOU WILL OR HAVE ALREADY DONE, ex. I will immediately ship the balance of your order and arrange for the incorrectly-shipped items to be picked up on delivery.  Your order should arrive this Friday.]

I sincerely apologize and hope that you will call me at XXX-XXXX if there is anything I can do to minimize the inconvenience this has caused you.

Sincerely,

[YOUR NAME, ex. Jill Jones]