Vodacom incompetence and inadequate customer care

I actually would prefer no stars. I have been on email, phone and FB messenger with Vodacom Customer Care for 2-3 months in relation to a complaint. They charged me for a contract that I had officially cancelled and they are unable to apply a credit note to my account. I keep having to email or call every month after they assure me that it's been resolved. They've sent me a credit note separate to my actual account! So the credit not has not been app****, I have not received a credit and they repeatedly fail to understand this. Every month I deal with a new consultant who tells me the same thing!!!!!!!!!!I should be reimbursed with interest after all of this!!!!