Dear …
I am writing to you in response to your letter dated __(date)__ wherein you advised us that you did not receive your order on time, thereby causing you undue financial burden.
We have had the opportunity to investigate this matter and have found that it was an error on our part with our shipping schedules. Please accept our sincerest apology for this oversight. We accept full responsibility for not complying with the delivery date that we had agreed upon and wish to offer you a couple of possible remedies as a means of compensating you for our error.
Option # 1
or
Option #2
Please contact me directly at __(phone #)__ once you’ve had the opportunity to consider these options. I would be happy to discuss them further with you.
You are a valued customer and I hope that we can come to a speedy agreement on the resolution to this matter. I look forward to hearing from you soon.
Yours very truly,