For other questions you may have, please contact the Office of the Tax Assessor-Collector at 210-335-2251 for personalized assistance. Application for Tax Refund Overpayments or Erroneous Payments.You may fill out the change of address form or simply make the request in writing. If you have an overpayment debt, you may be eligible to make a full or partial payment using Pay. Gov or your bank's online bill pay option.