Billed for contract that has ended

My contract ended in October of 2018 , i was told by your call centre agent that the number would automatically move over to prepaid nothing will be required from me , we informed her we will not renew and would like to cancel.She said it will automatically fall away

only to come to December and to see an outstanding bill of R1700 , when i contacted your agents via webchat their explanation is that we will be billed for data used and only pay for the sim card , strangely the sim card has been detroyed so we havent used data and why must i continue to pay for a contract that has ended.

on your website you say a customer can "Choose to keep the existing product for 6 months after expiry" , well there isnint much choice because i wasn't asked and i told your call centre agent that we will not continue with the line after contract ends.

pathetic pathetic i will never use telkom again , i want this bill written off because i never authorized or chose to keep this product going.