Samsung — Samsung M21 restart issue

1 year before I bought Samsung m21. I am facing restart issues from the last month. Exactly after warranty completion I am facing this. I have tried many solutions provided in the internet, even I have tried the solution given by the Samsung online support.

But no use. Now the phone is not in a working condition. Samsung service center is asking 8000 rs for motherboard issue. I found many of the Samsung M and A series users are facing this issues.

Please provide a solution for this. And Samsung don't loss your customers. A normal people buy a phone to use atleast 2 or 3 years. If it is get repaired in 1 year then what is the meaning of the brand "Samsung".