Defective notice issued u/s 139(9) [no error codes?]

Hi

I received an email with subject "Response to the Defective Notice issued u/s 139(9) for PAN xyz, AY 2013 – Reminder"

you are requested to
1. Pay the taxes due and file a corrected return u/s 139(9).
2. If you have already paid taxes then file a corrected return u/s 139(9) in response to the defective notice.

People receiving this message are given some error codes but I have not received any error code. I do not even know where my error is. I called ITR helpline but those guys are a bunch of fools and unable to help me in anyway.

Can someone tell me what should I do?

Thanks.