Bad customer service

I would like to complain about Maartens from MTN who dose not have good customer services. I went to complain about an incorrect cellphone billing 3 time at the MTN shop. I was told that must call limit was not activated but I still received an SMS for an incorrect deduction which was not according to my contract. I asked for a copy of the contract and he told me that it was my responsibility to keep it. He was shouting at me, which I made him aware of and he told me that was how he speaks especially when someone does not understand and he will not cry every time a customer comes with a complain. He was rude and he told me that there is nothing he can do if the call limit option on the contract was not selected. Sbonga Majola was a trainee and he was the one helping me with the contact and I specifically asked him for that option. Maartens was not helpful and I'm not happy with the way he handled my query. He even told me that he cannot view my billing for 2015. Is that possible. I was charged R1545 in march, R1848 in April, +/_ R900 in May. Please assist.