If a property tax bill was paid on the wrong real property by your lending institution by mistake, you need to meet with a representative of the county tax assessor as to the situation and follow up with a letter seeking a proper credit. You also need to get your lender involved in resolving the situation since it made the erroneous payment to the tax collector for property tax purposes.If you do not receive the desired result in the near future, you will need to consult with a real estate attorney as to the means to get the proper credits due you.