Mistake in 26as

it has to be removed from systems otherwise demand will keep coming

meet ao personally and get it done (no alternative )

reply to notice alongwith paid challan copy..

and Self Assessment will never reflect in 26AS.

many time it happens that refund is adjusted with demand 

(for  tax which paid  already  )

Self assessment tax not to be show in 26as

First of all check intimation of AY 2012-13. If credit of self assessment tax has not provided file a rectification application u/s 154. If credit of self assessment tax not provided after rectification application raise grievance on https://incometaxindiaefiling.gov.in.

You may raise grievance directly instead of filing rectification application but in my view it is better to file rectification first and then for grievance.

Further if tax is not shown in 26AS first check the PAN and assessment year stated in challan, if there is mistake, you have to approach with assessing officer to correct the same. If AO did not correct mistake lodge grievance on pgportal.gov.in.

The Income Tax Deptt has recently introduced "e-Nivaran" link on their e-filing site. Take advantage of the same & file your grievance giving details