Paying the gratuity in case of transferring an employee to another company

Hello,

I have been working with a free zone company for the past 4 years and as a part of rebadging, I am being transferred to another company.

My current company is denying my gratuity stating that it has been transferred to the new company which I am going to join, however, my new company has clearly stated that no such agreement was made and my current company is responsible for paying my gratuity.

Please let me know how can I proceed as my current company is not giving me my gratuity?