What to do when the employer is forcing me to work beyond notice period?

Hi madam,

I am working at a civil site for a contracting company in Abu Dhabi. I gave a resignation letter and working on the notice period now and it is near to finish.

I wish to leave the company because of some personal problems but today my company owner said to me that they cannot cancel now and I need to wait for more time here so that they can find a new person for this job.

So please tell me how can I get a cancellation from here?