Panasonic — Mobile suddenly goes dead

Sir, I am Narendra Paranjape, bought Panasonic Eluga L 4G ( IMEI [protected] and [protected]) on 4/07/2015 at Badlapur Dist Thane.. After almost a month of purchase my mobile got dead. I had to take it to service centre. I got it back in couple of days reason was not disclosed. After about 15 days the problem is repeated this is on 29/09/2015, it got dead. I gave it back to the same service centre. The service centre sent it to Head Office as I insisted on refund / replacement. I do not wish to accept the same piece after repair. As I have to travel a lot, I need a constant connectivity to my home as well my Head Office. If the mobile doesn't fulfill the function for which it is bought, it is of no use. Hence I request early action. How come the world renouned company is giving such product and service to the customer?