How to adjust unclaimed challans with the defaults amount.

I have so many unclaimed challans for FY 2009-10,2010-11,2011-12 due to non submission of filing in time. After adjustment of TDS filing defaults as much as possible, still some amount of default are pending for FY 2012-13 and 2013-14 which mostly of delayed filing levy and interest thereof. Please advise me how to nutralize the default amount with those unclaimed challans.