Account Errors and Negative Listing

I have an MTN cellphone account which I make payments into every month via EFT, but for the last 12 months I've made numerous attempts to get a hold of MTN customer service to first correct my email and contact details as I have not been receiving any statements ever since I've had this account. When I do get a hold somebody they say they will update my details but nothing has been done and when I request statements on my new email, I'm sent a link that requires an OTP which is sent to the wrong email. I have sent emails for these details to be update with no response. Subsequently I have discovered that I have a negative credit rating cause my account has been handed over to legal, which to date still has not sent me any communication about this. I've sent emails to legal to obtain statements and to enquire if they had been receiving my payments, with no response. I've even called 808 to ask legal to contact me and still no response. I need to get the matter resolved and settled as it is preventing from obtaining a bond. Could somebody urgently assist me, as it is unfair to have a negative credit rating if no attempt was made to contact me while I was still making payments