Urgent! ****************, still debiting my account without my permission for a contract that ended in 2017

My contract for my number ********** ended in 2017, and nodoby from Vodacom contacted me or neither emailed me( as normally before they would send my statements via email) so they can't lie they don't have my email address. Also they have my alternate contact details. Instead of calling me, they up till last month have been debiting my account for which they can even see I haven't used that sim for a year. I demand a complete refund of those debits which were after the contract ended. I shall not hesitate either to contact the Ombudsman as this is theft