Simply replace the unfilled areas such as "__" and "_[date]_" with your information.
Thank you for referring our company to _[name]_. We appreciate your effort in helping us reach new potential customers. We rely on references from our loyal clients to encourage our business, and you have certainly contributed. Rest assured that we will treat this referral as we do all our clients: with respect and courtesy.
I hope to hear from you soon, and on behalf of the entire team at _[company name]_, thank you once again.