Incorrect Username Change and Inability to Reset it

I would like to report an issue regarding an unauthorized username change in Minecraft Java Edition, which has resulted in the alteration of my username to "CozyIstSchwarz88" instead of my original username "9cloud9." Moreover, the system is not allowing me to rectify this issue by changing my username back to its original state.

I kindly request the assistance in resolving this issue and restoring my original username, "9cloud9." I would greatly appreciate any guidance, support, or solutions that can be provided to rectify this matter promptly.

Note: I apologize if this issue does not align with the typical bug reports on this forum, but I could not find a more appropriate place to seek assistance. Thank you for your understanding and help in resolving this matter.