Contract extended without my authorization

I had a cell-phone contract with Telkom that should have been ended on the 23-November-2023. I was paying R269.00. I had inform them early that after the ended of the contract I don't want any data or airtime from Telkom. I was then given a contract of R99 for 800mb wish I had reversed from the onset. They then continued for the next three months and every month I would reverse the debit order since I had never agreed to this. This month they took R911 on my account. I am disputing this as I had never agreed to contract extension.