Settled account but still owing

I have settled the school fees in full for 2024 and according to their accounts department where a lady rudely told me that they are there to run the business and their accounting method differs. i am failing to understand that eStatement in Jan 2025 reflected an amount owing. Their explanation was that after i settled the account, they still continued to invoice for the last 3 remaining months. I said to them but what if i was settling because we are removing the child from the school to another school? No answer. My statement keeps on growing and growing and honestly i am not bothered. i am paying what is due in terms of the fees and thats it. DO NOT SETTLE AN ACCOUNT WITH SPARKS. its a total waste of time. And the accounts lady's attitude reeks. This was the last email i wrote and had no response. Dear Accounts Department,

Please note that I am still in dispute with this account.

I still do not understand how after settling an account for 2024 that 2 invoices were still issued, which has brought this account to a negative balance. I then subsequently received another statement with a lesser amount due after disputing the initial outstanding balance.

I am still not acknowledging the 3 statements received in Feb/March 2025. Please reconcile one more time and revert.

Thank you, Keletso