BGMI Invalid Mobile Number Error, Recover Facebook-Linked Account

I am facing a serious access problem with my Battlegrounds Mobile India account. When I try to log in through the Gameplay Management System, the game brings up a window asking for a parent or guardian mobile number. Every time I enter my Indian mobile number 9662497***, the system immediately gives the error “Invalid mobile number” and does not allow me to continue, so I cannot reach my account at all. This problem has been ongoing for about three years, since 2023. I originally created and used this BGMI account by logging in with my Facebook account. However, now the screen never goes beyond the Gameplay Management System step, and there is no other working login method for me because it always stops at the mobile number stage and rejects this number as invalid. Since I cannot enter the game, I do not remember and cannot check my in‑game ID; the only concrete information I have is this mobile number, which I have always used. I am currently trying to access the game from a Realme Narzo 70 Turbo device. Because of this error, I have been completely unable to access my Battlegrounds Mobile India account for years and cannot use the game or any progress connected to that account. I kindly request your support to correct this issue in the Gameplay Management System, to accept or correctly update my mobile number and to restore my access to my BGMI account that is linked to my Facebook login. I also ask you to investigate the cause of this “Invalid mobile number” error on your side and help me recover my account as soon as possible.