Vodacom Overcharged Me & Still No Refund

I went in for an upgrade in April 2018 only to find out that instead of upgrading my cellphone account they upgraded my internet ****le. Which meant I was paying for two accounts and was being overcharged by almost R1200 per month. I raised this with them early enough so that it could be resolved before they overcharge me again in September, however again I was over charged. After almost a month, it seems they have now resolved my account and I will no longer be overcharged. BUT NO mention regarding the refund of R5000 that they mistakenly took from my bank account. Beyond ****ed off is an understatement.