Handed over to legals

I was handed over to legals for what I don't know, I have paid my school fees and whenever I write examination I pay for it. Then Intec College in May 2017 send me the statement that I owe the college R900 and I went to Braamfontein branch to get clarification why I owe the college , I was send to one lady at the office and come to think she can't explain that matter, then she gave me her office phone and dialled the number at accounts dept in cape town, and I gave the lady my student number for verification and to hear my story. The lady never heard what is my story , she just transferred me to the legal Dept and I said my story to the lady at legals Dept and she just asked me I have been handed over to legal dept and I have to pay that money and come to think I don't know why they billed me as I don't owe them any money. I need the college to give clarification on these matter.