Breaking the employment bond.

I am working as junior developer for a software company. While joining them I have signed a bond with my employer. As per that i have t serve till 31st October 2014. In case I want quit in between I have to inform them 2 months prior and in lieu of notice i will have to pay 1 lakh rupees as compensation as they have provided training for me. I have resigned by job on 06-05-2014 stating that i will serve the notice period and my last working day would be 06-07-2014.

But my PM is not accepting my resignation and forcing me to work for 1 year more saying that it would take 1 year for them to find replacement for me. And they have my original educational certificates so I am very worried.Would there be any negative consequences for me for bond breach? Can they hold back my certificates?