Nokia 5130 — improper service by nokia care centre

i am vishu i have a nokia 5130 mobile phone .i purchased it 3 months back. its imei no is [protected]. my phone gets switched off when i receive any cal. i gave it to nokia care centre at yp enterprises shop no 3 deep complex opposite doaba automobiles, amritsar. they took 11 day to for repairing and then aloso it had the same problem after i got it bback. they have send it to their haed office in delhi. they have reloaded the sofware 3 times but no repair is done till date. again i havegiven to care cente and now they asy that it will take 10 more days as they gonna send it to their head office again.
i request to see upon the problem and to change the hand set as iits is in warranty. warranty ref number is APAINY[protected]. THANKS YOU.