Vodacom upgrade nightmar

In August I upgraded my contract. Due to a technical error with Vodacom I never received my handset. (Iphone 8). After several calls and mails I finaly got the upgrade canceled and received credit for the 2 months that I paid for the handset. R433.19 per month. These credits were passed on 7 September 2018. I was informed by the hello peter rep that the issue is resolved and I can do my upgrade again. So I did, at the Istore. I never bothered to check my invoices again and realized in December that I am still paying for the handset I never received. R433.19. This is now for October, November and December. Can somebody with the right expertise and athority please help me. Acc no: I ********** -9 Upgrade no: ********** 407 My Tel: ********** 825