Misled and forced to pay for Mtns mess up

Last month I called MTN call center wanting to get a data contract. Joyce Kekana assisted me, she made me believe I was taking a 150 gig package for R350 she had explained to me that the 150gig data is made up of 120 anytime and 30 night data anyways turns out she had mislead me and that was not the case. I emailed asking for them to fix this or to have the contract cancelled and be out back onto my old data packages. I also explained I was not willing to pay migration and cancelation fees since I wouldnt have done both had I not been misled my Joyce. Her manager phoned tried to get me to take a more expensive package to which I refused, he tried to scare me by saying il have to pay cancelation fees. To which I asked for copies of the call since I was certain I was misl emails where Joyce specifically saying I will get 120gb day and 30gb night data. Till today I have not received a copy of the call. My contract was terminated and I was out on prepaid even though I asked to be put back on my old plan. I was charged cancelation fees and migration fees, after numerous emails, calls and contious nagging I was eventually told they will not charge me cancelation. Fast forward to now I am still charged migration fees and R427. 14 for the data plan even though it was for R350. And I had already been charged pro-rata data amount on the previous invoice so. I don't know why mtn is over charging me and why I am still charged for migration since it was mtns representative that messed up and misled me. I've tried emailing Joyce she ignored my emails and has blocked my calls she refuses to assist me in any way. Now I am stuck with a bill which I shouldn't have to pay but have no choice. I've also tried emailing mtn customer care numerous times and no answer or assistance.