Mu phone was working fine for 2 months after purchase then after I updated my phone after few days it startedglitching and sometimes screen was irresponsive. Mainly if suddenly the brightness is more or brightness goes down my screen stops working .

My phone was working fine for 2 months after purchase then after I updated my phone after few days it startedglitching and sometimes screen was irresponsive. Mainly if suddenly the brightness is more or brightness goes down my screen stops working . Even if the screen is on automatically it gets tapped and it gets into apps by it’s own. I went to the service centre and they reset my phone and it worked fine for a month and again same issue happened. I went to the service centre again and they did something which worked for few more days. I have gone there total 4 times and now they are not helping me out fixing the problem neither replacing my phone. What do i do?