Oppo Mobile — phone overheating

Address:

ERAYIL HOUSE, MAZHUKEER, Alappuzha, Kerala, 689124

I purchased a oppo a5s phone from chengannur (Kerala) qrs shope. From the beginning phone slightly heating but i ignore that but nowadays my phone overheating without use.. I informed previously the same shop from i purchased they told me that is happening due to the reason of software complaint, i submitted my mobile one day that shop for the purpose of software update. I don't know that people do that properly now also no changes from the past condition in my mobile phone.