Company usually writes in the appointment letter ' you shall have to abide by the policies of the company in force from time to time"
In your appointment letter company has written " Company reserves the right to change the terms & condition of employement any time." and "company reserves the right either to accept pay and allowance / adjustment of leave towards notice period or demand for actual service during the notice period"
And from all the points mentioned by you, it shall be appropriate that you use your rapport and ask one of your friend/HR persons for the way out, and tactfully wriggle out yourself.
If you have signed on the dotted line it does not mean that there shall not be any alternates, and best source to find it is within your own company.
Your boss is mean, carrierist,and clear that he shall under no circumstances take the onus for anything on him.
If you have some exigency at home, you may avail leave and resign and express inability to serve.
You shall have to find soloution to the responses of the company which may include delays in your settlement.
You may seel opinion from a local service lawyer.The appointment letter, which is contract, can not in prejudice to the rights of employee,and the employee can not be a bonded labour.