Well the top positions in MNCs a re most vulnerable due to grey area in the labour law in India.

The labour law in India does not give any protection to the persons holding in Managerial ranks in private sector. There is well crafted rules and regulation for such posts in public or government sector.

So in your case even if there is gross violation of fair practice or natural justice causing utmost injustice to you I regret to inform you that you do not have much legal recourse.

You can seek remedy for damages arising out of breach of trust but considering the time and cost involved therein it is not advisable at all to explore this .

So better quit this job which appears to be all but finished for you and joint another suitable job.

All the best.

what were terms of your appointment letter?

2) if your services have been terminated you would be entitled to salary in lieu of notice period

3) since you were working as head sales you do not fall within definition of workmen

4) A 'workman', as per the statute, is any person employed in an industry to do any manual, unskilled, skilled, technical, operational, clerical or supervisory work for hire or reward. The definition however excludes an employee employed in the managerial or administrative capacity; or in a supervisory capacity drawing wages exceeding INR 10,000 per month

You can make a written representation before the top management in this regard, obtain their reply even if it is not in your favor.

Then you may issue a legal notice demanding explanation for this ill treatment and compensation for having ruined your career by such activities.

This can be followed by filing a case before labor court under industrial disputes act for relief and remedies.