We are Pvt Ltd co. IT department has raised tds default interest on late payment of TDS. We have deducted TDS on commission 30th June 2012 & paid the same on 14th July 2012. So interesrt should be charged for 14 days. But IT department has charged us interest for 2 months @ 1.5% per month. Is IT department calculation is right? How can I challange IT department calculation if it is wrong?