Nokia/7210
Suddenly get switced off

Hi..i m princi... i had buyed 7210 set on 27/06, tin no-03421135401.Suddenly set get switched off. I had given set for repair to nokia care cenre, shop no-4, basant chownk, model town, jalandhar.but no result is found after recieving back the phone.i get switched off now also.plz help me.