Nokia N72
Speaker not working properly

I bought my nokia phone on 15 march, 08 . which is still under warranty period, whose speaker is not working properly even after i got it repaired from the nokia service centre in rdc, ghaziabad who are not taking much interest into the matter... As nokia is the most leading and trusted brand for mobile phones in our country, so it must look forward to its customers grievances.therefore its my humble request to take this matter seriously..hoping for a immediate redressal from your side...