Leaving the UAE before receiving labour dues to avoid overstay fines

Dear Madam,

My limited contact finished and the company didn't renew the contract. The visa validity finished on 11 April 2020 and I am in the grace period now.

Until now, my company didn't settle my dues including the leave salary and gratuity and they are forcing me to sign the cancellation papers without giving the pending dues including the exit air ticket. My passport is with the company.

What to do now? Seeking your advice on this situation.

How long they can they hold my passport & do I get any fines for overstay if I didn't sign the cancellation papers even after the grace period?

Please advise.