Contract ended and vodacom is still debiting

My contract expired in August 2020 and before it ended they called me for an upgrade and I told them I'm not interested in upgrading, end of September they've debited R257, then in October I spoke to one of the consultant to cancel this contract as it has expired, then again end of October they've debited R157 which I reversed and on my credit report it showed missed payment, now on the 2nd of November they've debited R257 AGAIN and I don't know for what, Vodacom just keeps on ********ly debiting money from my bank account.. I'm really tired of this nonsense... now my credit record is dented because of their *********** consultants and poor system that refuses to cancel contracts which have ended, What do you do in this case because my contract clearly states 24 months of which has lapsed and I was not even using the sim card it was just the device that I was interested in. I