Nokia mobile model 1255
Not able to make calls

I bought my mobile in the month of feb and in the month of august it stopped working and gave is to nokia service centre. they initially said come back after 15 days but that went up to 4 weeks, but the hand set is not working till to date.

if a new handset stops working within 6 months only what is the use of buying nokia. and again the service centre is also not functioning properly.

what should i do? is this a punishment for choosing a nokia mobile.

please tell me the solution