PC training account

I was a student at PC Training College at Cape Town Campus in 2012 but I dropped out because my parents couldnt proceed with studies payments and I was informed that I cant be able to continue with my studies while my account is not up to date but now im suprise im receiving calls from credit collection regarding the account that I owe + 20 000. Im failing to understand why I should owe that amount but I dropped out because I was informed that I cant continue with my studies while owing.