*****ulent debit order

My wife's contract had finished and we gave them notice to say we will not be renewing the contract. However they telkom sends us a bill for just over 3k saying that we ow that due to canceling early which we didn't. If we took a contact in april 2021 with the 1st payment in may 2021 after 24 month the final payment would be april 2023?? I have no clue what calender telkom uses but they say it expires in july 2023 to our amazment. We then query this with them(using a different number as they have blocked my wifes number from contacting customer care) they open a case then send us a mail saying the case is clised and debit my wifes account. This is ***** and we will be opening a case at the police station for *****ulent debit