Vodacom Blacklisting my name for no reason.

I have been querying with Vodacom about my credit update on the credit bureau's for a contract that I finished paying in 2020 already but on my profile it says I am in 6 months arrears. I have called Vodacom to rectify this and they have not been interested to assist me in any way. I have also requested a paid up letter countless times and not receiving it. I called their complaints department where they said they would investigate and they did not get back to me with any feedback. Vodacom is getting me stuck on credit applications.