No options left to resolve issues

I have had an impossible time with the MTN legal department. They have not managed to resolve a query from over 6 months ago and after following up countless times they just stop responding.

I have raised the issue with the Experian and the credit ombud as it is impossible for me to resolve this internally. Calling the call centre is unhelpful as you get put through to the wrong department and are not taking calls. I feel I am out of options to resolve this.