Your employment contract, what does it say about misbehavior redressal. It would be better if a soft-copy of the employment contract and the warning memo be sent to firstname.lastname@example.org. I will give them a read and give advise correctly based on that instead of giving generic advise.
For further queries, you can also contact me on 7601090391.
You can call me for advise on mobile no 9359867870