Income Tax Refund

Sir. for F.Y 2005-2006 and 2006-2007, it was found that the income tax refund of Rs.10 lakhs each was not received. Income tax returns were filed while showing the income tax refund in ROI and subsequently due to non follow up, it was skipped, now we found that for those two years refund was not received. So, kindly give opinon as to if I start follow up now, what are the chances of getting them.