Blue Screen solution please help!!!

I get this screen and the laptop shuts down in the blink of an eye when I operate on multiple tabs. However the timing is unpredictable. I got RAM changed, now the frequency of shutting down is less but still there around 3-4 times a day. The problem is when I use at home it shuts down, i don't know why not at the shop. And the shopkeeper challenges me that he can't do anything unless it shuts down. I went to the service centre to get new windows uploaded etc, they simply said we already told you it's Motherboard issue so your 850 rupees will only go to waste. my excel and word files are going into recovery because of computer shutting down and the laptop is giving no solution. Inspite of all videos etc,the shopkeeper says I can't do anything unless it happens in front of me. What to do? My father is getting very happy that it doesn't happen at the shop so he doesn't have to spend a penny 😂 but it is me whose work is getting disrupted.