how to retrieve my line that was deactivated

Hello, It seems my MTN no has been deactivated. It is saying not registered on the network. I left Nigeria in 2019 to study abroad and i have always ensured i load credit on the line as well as send messages and receive calls occassionally. The last message i sent was in October 21st 2025 and the last call i received was 26th October 2025. Please i want to retrieve my line .