Vodacom has threatened to suspend my number after I clearly communicated my desire to end my sim only contract in February already

Vodacom has threatened to suspend my number after I clearly communicated my desire to end my sim only contract in February already. All I want is to be a prepaid client. They won’t contact me or release me from this contract. Why does it have to be so hard. I’m going to the ombudsman. They have no right to the massive penalty they expect me to pay. I know my rights.