Dropping of demand notice

Dear Sir/Madam,

I am salaried employee. For the year AY : 2010-11 which i failed my IT returns through offline (paper submission). Recently when i logged in CPC website, i saw there is Demand Notice for that AY for the amount of Rs.4500, which i had paid the amount by eChallan online and is reflecting in form 26as for that year.

But My issue is, the Demand notice in CPC website is still not removed and is appearing , even after i paid that amount.

Please advice , How should i proceed.  If there is any letter that i should write to , please provide the format of the letter. Thanks for your help here.

Regards
Naga