against new mobile purchase

Dear sir,

I have purchase new mobile handset (Samsung A-5) from Reliance digital show room kakadeo beside silver spoon restaurant, from next day it has battery backup problem, heating problem during charging and hanging problem, during this problem i went to the showroom where i have purchase the mobile, they suggest me to go to the company service centre and tell him all of your mobile related problem with them but when i go there they told me that your mobile is ok i will change your handset battery and it will going to the perfect but i told him that i won’t get this hand set.So please replace my handset from new one. but they did’nt me D.O letter for new set.
Kindly book my complain against samsung service centre kanpur branch R.R Entreprises 96/2 Star Press Building Colonel ganj kanpur-208001