Promises, Promises & ****py Service!!!!!

I have been in contact with Vodacom since November 2020 regarding a contract that I want to cancel with them. I canceled the contract in November 2020 but in December 2020 I received an invoice that this contract was still active. Trying to speak to a competent person during December was a hassle so after receiving an invoice again for January 2021 (with an increased price) I phoned them on the 5th of January asking them to cancel this contract with immediate effect and organize a refund for December 2020 & January 2021. The agent that I spoke to that day said that the cancellation has been processed & an agent will phone me regarding the refund in 24h to 48h. I never received a call or confirmation that this contract was canceled or that a refund was going to take place. I phoned again on the 19th of Jan & 27th of Jan. The cancellation eventually went through on the 29th of Jan. I phoned again on the 1st of Feb to make sure that this cancellation went through, the answer was yes. The morning of the 2nd of Feb I got debited again for this contract. I phoned again today the 2nd of Feb and the only answer I'm getting is that this matter will be escalated to a Manager and that this Manager will get in contact with me. I've been phoning almost every 3rd day since hearing the same story " This matter has been escalated to a Manager and they will get in contact with you in the next 24h to 48h." I'm so fed up with taking the time to phone Vodacom & to hear the same story. I've been BEGGINg for a Refund for the last 3 months!!!!!!!!