Micromax — About my mobile

i m give a mobile because i have sent my mobile to a delhi micromax company through kalyan micromax gallery for repair my mobile was dead then my mobile has come from delhi within 15-20 days but mobile has worked hardly 7-8hrs not aslo work 24 hrd and i have purchase mobile before 3 month it is a default peice plzz replace me that mobile plz i kindly request u and in gallery they dont giving me a standby mobile for use