samsung galaxy grand2 – damage handset

dear sir,
i brought samsung grand 2 in mobile store on bajaj finance on dated 15/05/2014 when he give me hand set he is not work normaly he did not swich on i tell h im handset is not work normaly give me other new handset but the seller in mobile stre was say me this is a new mobile he work normaly 1 or two day after i take him and next two days after handset in hitting over and hanging noise and lines on the display i take and tell the mobile store seller same problem but he did not agry with me he tell me use it four to five days when i take the handset same problem when i give to service center the mobile he say software problem install it new softwre and give me return i say i want new handset this is adamage handset but he not agry with me but next three days the handset is giving same problems mute and display on of and last he is dead thjen i take it and give in mobile store in kalyan he take go to service center on dated 15/05/2014 but he is not repair now on this date22/05/2014
but sir i dont want this repair handset i want a new handsetbecause thehandset is already dammaged when i brought the mobile store is cheat meso please help me this matter.
thanking you