Dear :

I'm sorry that the [products] we shipped you on [date] did not fulfill your expectations. We are happy to credit your account $ for its return or send you a check for the same amount.

If you are interested in other models, please take a look at the enclosed copy of our lastest catalog. We'll be happy assisting you with another order.

Hope to hear from you soon.

Sincerely yours,

[name]

[title]