Bad service from Education Alive School that I had to pay for!!!!!

I went to the school in November asking for a full year statement and I was told that I must settle R600, i did so. Yesterday I received a message saying I owe R550, I became furious as I was under the impression that fees were up to date and I decided to call Mr Ndaba whom speak to me in a polite manner and asked me to find out from accounts which I did and the lady explained that they made an error by saying the amount due was R600 as a matter of fact was supposed to pay R1150. I don't have money waiting in case someone made an error, I wanted to find out from the school as to who is reliable for that error and I was told to speak to Mr ****son who refused to give me his full name as he was so rude. Wow what an experience of a bad service.