No dismissal of rectification request barred by limitation if intimation wasn't served to assessee

IT: Where intimation issued under section 143(1) on 30-6-1999 had not been served on assessee and assessee in March, 2006 having come to know that credit of TDS amount was not properly being granted to it made an application under section 154 on 20-3-2006 seeking rectification of impugned intimation, Assessing Officer was wrong in dismissing rectification application on ground of limitation prescribed under section 154(7)