Terrible Service

I'm writing here with tears in my eyes, and I am so drained by the appalling service I have received from MTN. I have received a sales call that was offering a contract Sim card with data back in 2022. At the time the Sim card was sent to me with 20gb and I tried using it and did not work and I threw it away. I never thought it would affect my credit as I thought it was subscription however not the case. Earlier this year I have discovered that it was appearing on my credit score and I could not apply for any credit because of the account. I have been in and out of MTN stores for assistance, I have also took the initiative of calling the customer service team several time and was being passed from pillow to post and this has been going on for more than 4months now and still not getting anywhere. Instead, the store would tell me they cannot help they will email legal team as they do not have a number to call, and they never got back to me. Got through collections and retentions team and they have been telling me that the account is on a 0.00 balance, and they are unable to send me written off letters or settlement letters. It's not a matter of not wanting to pay the account or anything but they not telling me what I'm owing so that I can pay the amount. I am so defeated right now,Mtn has failed so much!!!