How worst Vostro 3400 is

I bought Dell Vostro 3400 In October 2021. I only use the laptop for MS-Word & PDFs and basic web browsing and nothing else. Yet since after September 2022 my laptop started having issues and would not start. Whenever I start my laptop it shows "No bootable Device found" and only provides option of "Shutdown"  

And even it if laptop starts it crashes down and shuts down in between. 

I have shown it to a technician of Dell from the store that I bought. He formatted my laptop and gave it back to my saying the issue is resolved. It after like 2 days I started facing same issue with my laptop. 

Like how worst can a laptop be when it cannot even handle Ms word & PDF. This laptop is utter waste of money. Never buying Dell laptop again.