Nokia/3230
Lack of services in repairing

I purchased a Nokia 3230 cell phone on 21/12 in the month of October it started giving problem the type of problem was the display of my cell phone started flickering. In the start of Nov I submitted my cell phone at Nokia CarePoint for repairing since then I have submitted my cell phone 4 times because of same problem. Still it is at Nokia Repair Centre.

Now I want replacement of my cell phone and it is covered under the warrantty but Nokia Officials are sleeping there is nobody to hear my complaint. Please help me out.