Angry and Frustrated

I've purchased a MTN cellphone package via CCISA at the end of 2018. While finalising the contract I was concerned about the amount of R99 for the package, but the salesperson reassured me that R99 will be the fixed amount payable on the installment. However, after receiving the cellphone package, an amount of R406 was dedicted from my account on a monthly basis. As soon as I noticed this error, I've made contact with MTN only to learn months later that they cannot assist me with this matter.

After being refered back to CCISA, I was in contact with a person named Xolisile who was supposed to find out why I am paying more than the agreed amount of R99. I have made several attempts to get hold of her and I am utterly disgusted by the fact that she has not gotten back to me in months. I am not usually one to complain but this type of service is pathetic and completely unacceptable. I need answers w.r.t why I am paying a whole R306 more than what I am supposed to. I am annoyed and frustrated and feel like my rights as a customer has been violated.