Early termination of limited employment contract

Hi. I am employed by a DMCC company with a limited contract. I have finished 1 year 3 months to the company and decided to leave. As this is a small company wherein operated by just me and my boss, he doesn't want to release me till we found a replacement. I am serving my 30 days notice period till 21 of this month and on process of finding a replacement (interviews ongoing).

My question is if he wasn't able to find a replacement till 21 of this month, does he have the right to force me to extend my service? He keeps on threatening me that he will file a case and make a problem for me in mediation and labour.

Please help. I am willing to pay the 45 days early termination fine. I just want to leave the company. :(