I have found that I overpaid tax a number of years ago (8), but only recently was able to receive the evidence of the overpayment from my old employer recently. I have submitted it to the ATO but they are asking why it took so long? Am I right to think that they have no right to ask this question? The fact is I overpaid tax and ATO only has the authority to tax in accordance with the law? What is the best way to respond. Grateful professional views.