Paid up letter dispute

I have settled my account in 2023 with MTN directly however I am still listed under their legal department. Requested for a paid up letter from 2023 to 2026 from them they refuse to send it claiming I still owe them yet I paid up in full. Mtn refuses to assist me I have sent numerous emails to CIM, Back office, Retentions and Pos Paid no help. BA***