D- South Society,
6 January 2012
<Mention recipient’s address>
Dear <Recipient’s name>
This is to inform you that we have received your payment of <amount> on invoice number <invoice number>. Because <specify reason for overpayment> you are due a credit of <amount>.
<mention the action taken for handling of overpayment>.
For any queries, please feel free to call us at <phone number>.
encl: <Mention list of enclosed items>