Fail to rectify contract

In December 2014 I did a upgrade on my cellphone contract. Late January 2015 it came to my attention that I was not receiving all the data and sms's as stated on the promotion. I contacted the shop where I did the upgrade and spoke to a person by the name of Kelly, who did the upgrade originally for me. He said he would look into the problem and phone me backbut he never phoned me. A week later I was at another Mtn shop and asked if they could rectify the problem for me. They could not help me and said it must be done at the shop where the upgrade was done originally. They phoned Kelly who told them he will look into it and phone me back. Again it never happened. The next week I went to the shop in Bethlehem to have the problem fixed but Kelly could not help me. He said that MTN should fix the problem as they loaded the wrong package. I then spoke to a the owner of the shop, Dirk. He told me he will have a look at the problem and phone me back. It also did not happen. After that I went to the store several times but the problem could still not be fixed. I am currently paying for something which I do not receive and it is unacceptable