OnePlus India — Nord 2 not working

Dear One Plus Team,

I purchased One Plus Nord 2 on 8th Feb 2022.
Since I purchased this device I am facing multiple issues like:
Unable to disconnect the phone
Phone is hanging
Sometimes it automatically re-starts
Abnormal charging
The phone becomes unresponsive
Phone Details:
IMEI Number: [protected]
OS Version: V11.3
Version : 8GB RAM +128 GB

Recently I have taken this phone to a service center near me. They have changed the OS and given it to me and within 3 days I am again facing all these issues.

Request you to help me on this matter continuously I have been connecting to multiple one plus support services and yet have not received any permanent solution for the same.

Investing a good amount on the phone is making me struggle a lot every time after a call I have to restart the phone, which is very problematic for me.

I hope you can understand my pain & provide me with the best solution.
Awaiting a reply ASAP.