MTN service is so bad

MTN provide the worst service ever! I have an MTN account that is listed on my debt review. Phoned and email several times to obtain a paid up letter, and all they tell me is, the account is too old, they dont have the detail so they CANNOT assist me.

How on earth do you give such an answer to your customer? How am I suppose to get out of debt review if they dont want to assist. Emailed their legal department, they have not even respond. been weeks now, not getting anywhere.