UNHAPPINESS WITH MTN

At the beginning of June I renewed my contract. I chose the iPhone 7 that was on special for R288 - specifically asked for this one as it was only R10 more than my old contacts. When I received my acc at the end of Jun the amount was way higher than it was supposed to be and I was told that it's a once off thing. At the end of July and August I was charged R399 instead if the R288. After NUMEROUS of phone calls not answered and emails not answered I received an email asking for a copy of my contract - where's their copies? Now Im told but that's the contract I chose! I still asked the guy instore - it's the R288 one? His reply: yes. Now what? They see the case as closed! With my old contract I NEVER had to upload extra data, etc, which now is not the case.