Nokia — mobile stop the working

Hi,

i have purchase one Nokia 5 phone from Rahul communication Indira market Mandi Himachal Pradesh in Jan.2018 but one day Apr. 2018 we do the video call in my home then suddenly the phone is stooped he says me your picture shown black but in few seconds phone display off and not restart again, when we discussed this with shopkeeper he says you can go are center this is not our responsibility, when we give it in care center he says it is not repaired if you want to repair this then we will repaired but warranty is close for next time, so request to you please help me on this because i am a middle class person and not by phone in every three or five month