I want to take this opportunity to tell you how impressed I was with the service I received from your organization on __(date)__. In particular, I really appreciated the __(briefly describe what stood out in the service)__. It is evident that __(Name of organization)__ places a great deal of emphasis on good customer service.
Your employees are courteous, attentive, thorough and efficient. You should be proud of each one of them. My overall experience with your organization was a __(pleasurable/pleasing/etc.)__ one and I would definitely recommend __(Name of organization)__ to others.
The standard you set in your industry is that of excellence. I commend you and thank you for your superb service.