To request a tax refund, file an Application for Refund - Sales and Use Tax (Form DR-26S) or Application for Refund - All Other Taxes (Form DR-26). If Shared Services is not notified, the overpayment will continue.I am requesting a refund due to_____________________________________________ . The Benefit Recovery Unit reviews the case and establishes a claim if an overpayment has indeed occurred. The OIG determined that DTPW overpaid PPI not in compliance with the. Contract.