Pathetic customer service. Incorrect data issued

Am extremely upset.i took a contract with MTN last year since then I have had endless problems that never seem to get solved. Firstly the consultant entered the wrong deal. I wanted the 20gig day and 20 gig night promotion deal however I noticed that I was only receiving 10gig day and 10 gig night. I complained and the issue was resolved quickly however since last year December I noticed that my data was finishing quickly and when I checked I noticed that the issue had occurred yet again. I went back to Clearwater mall to sort the issue out I then called the call centre and was informed that I need not go to the mall because they will be able to help me. The assistant asked me to provide her with the proof of contact. I did so however I did not receive a reply and the matter continued to occur mind you this was in January. I still paid the full amount however I am not receiving the what I signed up for. I call the cal centre ND yet again i am given false promises that the issue will be rectified within 24 hours yet up till today I am still not receiving what is due to me. I call the call centre for the third time and I am informed that I need to go back to the consultant who assisted me at Clearwater (you can only imagine how frustrated I am) the agent assured me that the matter will be resolved however yet again I am paying for something that I am not receiving. I am extremely upset and dissatisfied with the ridiculous running around and going back and forth. Mtn is very quick to suspend their services when you do not pay however they do not deliver on their end. I have wasted so much of money and when I asked to cancel the contract I was told that I can not because I had taken router with the deal. I am extremely upset.