Ay 2012-13 - can we change schedule vi -a now

I filed AY 2012-13  on  10/09/2012 .   It came to my Notice that I have not taken L&T infra bonds under sec 80ccf over and above 1 lakh. 

I uploaded revised return on 17/10/2012 taking 20k investing in L&T bond under sec 80ccf.

There is a difference of 3.5k in refund

My original Return of 10/09/2012 was prosessed and  i got a refund of 3.5k less. The revised return was not  processed.  

My question is whether I can file rectification return online with only data schdules change with entry of  20k under 80ccf in sch VIA. OR

whether i can request for  assesment of revised    Return.