Staff incompatance,staff don't get back to you,

I upgraded my contract on August 2017. The consultant didn't only give me the wrong package they also put my package on a 36 month contract instead of a 24 month contract. I am between cape town and Johannesburg so don't have time to keep on going to the store. I did go to the store early January to sort out this problem. I was helped by a consultant who said that he will sort it out and get back to me. I am now in Johannesburg and I have been waiting for this consultant to still call and sort out my problem. I have called the branch on numerous occasions and no one answers. How can you run a business this way and what kind of customer service is this? I have been with MTN for the past 20 years and this is how I get treated from MTN. I have 4 lines on my name. How do I get this problem resolved. I am on the verge of changing service providers. I will not refer anyone to MTN ever again. I am quite sure there are other people out there who has had this kind of problem. Hopefully someone at management level can read this and try to help me.