Response to the outstanding tax demand

We all know that, Income Tax Department has stated new option "Response to the outstanding tax demand". Under which we can view & submit total outstanding tax demand till date. An Assessee has outstanding tax demand for AY 2010-11 (Rs.20,000/-) for which IT Return is filed manually. This demand is determined by AO. In September,2014 he has paid his demand amount by challan which is reflection in Form-26AS. Now, still it is showing as an outstanding demand after payment. The Assessee has submited his response as demand is correct. But after making payment of said year, demand is showing. What the Assessee will do now?

Thanks in advance