In your appointment letter company must have mentioned about notice period and notice pay.
Your notice period can be maximum of 2 months. If you wish to leave earlier than that you may inform the company in writing say 7 day before the date you intend to leave and you are liable to tender notice pay, for the balance period of your notice. It shall be a good gesture to inform in advance and it can be your defense if company makes any allegation against you. You can mention that you are willing to transfer the knowledge to the new employee. Submit the company property and under acknowledgment with seal and signature and obtain NOC/NDC. You should finish all assignments on hand. You should use your rapport, goodwill, and obtain a written confirmation that you have completed the tasks assigned to you. If you are not given the same you should submit a written communication with a copy to you and place on record that you have completed the task and nothing is pending to be done by you.
If you know that company has not recruited any employee to replace you, you can point out in your communication that company has not recruited any one although you had mentioned it to your authorities that your replacement may be inducted and you shall cooperate to transfer the knowledge and train the new employee, and rather now you are being pressurized and coerced and threatened to increase the notice pay and you are facing harassment in your everyday’s work.
From the day you have tendered your notice of Resignation Company has to make their arrangement to find your replacement, train the replacement, and put the new employee on the work. Company also knows that it can relieve the employee by disbursing notice pay.
You should not abscond. Settle the matter with your reporting authorities and leave with a happy note. You are within your rights to get acknowledgment of your resignation, work experience certificate, F&F,form16, PF accumulation reports, PF withdrawal/transfer forms, payment of you dues, etc.
Get your leave sanctioned from your authority for the 3 days you have not attended office.