Income Tax Refund Failure

U can do rectification in itr, which is a opened window on e filling potral

Pre-validation is very simple
Log into eFiling site and go to Profile . under it use pre-validate button and screen appears for validating. You can add, delete bank account. Follow the process and within 2-3 days you again check the status and confirm validation.

CPC releases refund only after bank account is pre-validated. So in a way compulsory to get refund fast.

After that you use Refund Reissue request facility.

First link pan with bank account. Then submit refund request at the portal.