BAD COMMUNICATION!!!!!!

So my child went to Hansel&Gretel last year. towards end of November I went to the school to enquire about outstanding balances on my child's account... They gave me the figure, so i settled cash, and the other was a stop order. I go to the school again last month as the stop order went through for January but my child is not enrolled with them anymore. To my surprise they could not find my child's account, it's like she never existed at the school. But all of a sudden the school has handed me over for some R1000 and odd rands which i cannot understand from where it came cause they could never find my child's account when i needed to settle it. I'm glad my child is no longer in that school, and i will not take this lying down. They are not even answering the phone all a sudden, what nonsense