Notice under section 143(2)

We have received a Notice under section 143(2) from I T Department for AY 2012-13 on 10/09/2014 within 6 months from filling of Revised return on 24/01/2014. The original return filling date  was 29/09/2012 and accordingly the Notice issue due date was 30/09/2013 (i.e. within 6 months from the end of year in which return filled).

Now my question is that whether notice issued by I T Department u/s 143(2) is valid in law on the ground that they have sent the notice taking the date of filling  as per revised return and not on the basis of Original return??

If department is not correct then what remedy do we have for the same ?????