Recover My Google Account After Unauthorized Recovery Email Change

I am writing because I have lost access to a Google account that is very important for me, and I would like your help to recover it. I live in Bangladesh and I was using a Gmail-based game account (linked with a Gmail address) that I had originally bought from someone. After purchasing it, I did not immediately add or change the recovery Gmail. Later, someone who had my phone in their hands added or changed the recovery Gmail to their own and took control of the game account. Since then, they have effectively “bound” the game account to their own Gmail and I can no longer use my game progress, even though the Gmail address itself still exists. I have not been able to access or use the game account since 2 June 2025. The game account UID is 6638301685. I did not give anyone permission to change the recovery details or to take over this account, and I believe my account security was compromised when that person held my phone. I kindly request that you investigate this situation and, if possible, help me regain full access to my game account linked to my Gmail or restore my game data to an account that is securely under my control. I am ready to provide any additional information or verification you may need to confirm that I am the rightful user of this account. Thank you for your attention and support in resolving this problem.