Snapdeal — Remainder for repair/return the product

Address:

Aligarh, Uttar Pradesh, 202001

Hello dear
I sumant chauhan purchase a xiaomi device name mi 4i mobile through snapdeal in month of january, after that there is hanging problem and heating problem the mobile during the charging.
I visit your service center name "pulkit computer service in aligarh up" for that problem but deny the service center tell me he can not give the service because your device is unboxed so we are sorry for the service. now what i do tell me proper solution.
My device imei is [protected], [protected] and attached invoice which is send by snapdeal. so plz help me