Samsung — Samsung Mobile E5 - Stopped working within 9 days

My Mother Purchased Samsung Mobile E5 on 13/3/15 to give me as gift on 17/3/15, I opened on 17/3/15 and start using the sane. After 5 days suddenly..Its Display was blank (23/3/15).. At the same time it was receiving calls. i waited for Display for 3 days with patience... But no use... Then i deposited the same with Samsung Service Centre on 27/3/15.. Now this new mobile is with them... On asking.. they tells cause of non-displaying is not being identified... They asking to wait... As per such case.. Samsung Centre should replace mobile immediately... i have spent 15000/- for this mobile and this mobile is with service centre... This is really very depressing... Excitement of getting new new mobile is finished... Please hekp me in this matter My Cell no is [protected]... Suggest me what should i do ??