MTN contract.

My credit bureau reflect that I have an account with MTN and at the same time they debit my account. I have never app**** or agreed to a contract with MTN since have closed my account with them in FEB 2021. This year I am told I have active account with them. Can you please sort this thing out because my credit record is being affected now, and I can't enroll my child into a school that I want because of this.