unhappy client

I paid Nairtime in full last year 2023 for the advance I took and the account was closed. It was shown as closed account. Recently it appears again and blacklist me for R1 that I don't even know what is for. When I called them, the lady I spoke with told me that it was a system error and that will be fixed by the end of July 2024. To my surprise the account is still appears and in arrears. When I called again the very same I called, no one is answering saying I must leave a message. I sent numerous email to them but no answer. I'm sitting with a mess credit score because of Nairtime