I was shouted and yelled at

I called MTN to inquire about the airtime that I've received and data bundle since I've cancelled my contract. During our Call Phindile just raised her voice and shouted at me and she told me that she did that because she wanted me to understand since she was repeating herself. I find this behavior not professional at all because I tried to tell her what I was told before cancelling the contract but she just yelled at me. I'm very disappointed at the service I've received from MTN after holding and waiting for an operator for 30 min. Call ***