CONTRACT EXPIRED BUT THEY STILL SAY I OWE THEM

I joined Cartracker in 2020, had a contract with them for 36 which expired in 2023 December 2023.. apparently i was suppose to call them after the 36 not to continue with the contract ,,I called them on February the 21 not to continue debiting my account , i was told i was liable for cancelling for at least one month fee which is R109... WHICH I UNDERSTAND BUT APPARENTLY AN INVOICE FOR THE WHOLE YEAR OF 2024 WAS ALREADY ISSUED AND THEY PROMISED TO CANCEL IT SINCE I HAVE CANCELLED THE CONTRACT BUT IT LOOKS LIKE IT WAS NEVER CANCELLED, COZ EVERYDAY IM GETTING CALLS ,EMAILS THAT I OWE R1070 FOR TRACKER ,WHEN I SAY TO THEM I HAVE CANCELLED WITH THE CANCELLATION DEPARTMENT THEY SAY DIDNT RECIEVE ANYTHING FROM THEM YET.