Samsung - Samsung auto restart issue

I had ordered Samsung M** mobile on *th July **** and received on **th July ****. After ** months recently I have faced auto restart issue in my mobile. I thought it's because of some error during phone update. So i checked for further update and downloaded, installed that also. After that also i have faced same issue. Then i had taken Samsung consumer care support and they connect to my mobile by Samsung remote app and they suggest me to do some check up by going into safe mode. In safe mode also i was getting same issue. So I have visited Samsung authorised service centre. They checked and told that Samsung M** is getting this kind of issue more recently and change of mother board will be the solution for that. It cost more than **** for replacement. But i have asked them to do software flash in my mobile. After software update phone was working fine for one day. Later i started to install applications issue started again. Then I have decided to do complaint against them to making this kind forgery to their customers by giving update make defect in mobiles and ask them to replace motherboard. This looks like they are forcing their customers to replace motherboards for their software issue. Also I have searched in internet and found there are many of the Samsung M and A series customers facing similar kind of issue. I want to make complaint to Samsung and take severe action against them.