How to claim back rental cheques and security deposit after early exit from tenancy?

Salam,

I have terminated my tenancy contract early on.

On the 4th month, I notified the landlord through his agent that I got released from duty and need to terminate the contract. I gave 2 months' notice (via email). I received verbal confirmation that I can vacate.

I received Clearance Certificate and handed the place over on time and in good condition. The only thing, I didn't pull out the balance cheques from the landlord.

1. The landlord didn't return the security deposit.

2. To my surprise, the landlord cashed the 3rd cheque.

3. The landlord still has the 4th cheque.

Being new in the UAE, what am I supposed to do?

How can I collect my money and stop the 4th cheque from being cashed out?