Very very rude consultant

Such a minor case that left me with a bitter taste in my mouth. I purchased all net minutes of which I was left with 2minutes. I made a call that lasted for 59 seconds and the second call for a minute but for some reason I was instead charged airtime. I called in to mtn to understand the cause of this. It was like I called a different company 1. The person just said Hello, I just knew that I will face problems because no introduction whatsoever but I had to continue because I made the call 2. She told me what she sees in her system which is different to what I have done. I even requested to send a screen shot to prove my argument. She made me feel like I'm stupid and never gave me options 3. I got so upset and my voice went so high and she was so rude and dropped the call while I was talking. 4. I'm still in shock. I don't believe that you have such employees. She didn't even give me her name even after asking.