Nokia 6300 — flickering on screen

Nokia 6300 — Flickering Screen

I have bought Nokia 6300 with IMEI no [protected] on 22/4/2008.I have a persistent problem with its screen.Screen of my set flickers whenever there is any outgoing or incoming on the cell.I have already submitted my cell two times in the nokia care for the same problem.but after few time of repair the same problem occur in the cell.This time again i am facing the same problem.but when the last time i submitted my cell in the nokia care they intimated me that i have warranty till Feb only, although as per the date of purchase warranty should be till April..Now suggest me from where i should get my set repaired so that this problem will not arise again.