Tds interest

hello everyone, i have received demand notice for interest on late payment of TDS deducted under section 201(1A). date of TDS deduction is 19/7/2012 and date of deposit of TdS deducted amount is 8/8/2012, so my liablity of interest is for 1 month only but in justification report they have demanded interest of 2 months. please guide me what should i do now????