Pathetic customer service

I have a billing query since July. Have reference nos and chatted to various consultants. To date this has not been rectified. Mtn *********** customers once again and not being able to resolve queries. I am highly frustrated with the incompetence and consultants promising to assist when I am the one having to call in, follow up on email and still 3 months later this has not been resolved. I am at a point of wanting to cancel my debit order then maybe they will have reason to call me.