a letter to a former client/customer who has decided to discontinue their professional relationship with your organization because they are dissatisfied with the service and/or product provided. Indicate you've given thought to their concerns by respectfully acknowledging their point of view, but make it clear that you are in the right by explaining why their criticism is unwarranted. Note that an acknowledgment doesn't necessarily mean you agree with the other party's position. You can disagree while still being positive in your tone.