Billing

Recently I just become a vodacom costumer since I have a contract with them. The issue I have with vodacom is my billing. On 2021/02/26 I was charged R806. 41 instead of R291. 56 and when I call them more then once I would say, I was instructed to send them proof of payment for the so-called month I didn't pay for. I sent one of the employees proof of my payment (bank statement) to *** . Sow far one has gotten back to explain my situation and in fact they debiting me even recently when they still owe me money. When i miss a payment get charged for missing a payment which they did. Who charges them when the don't keep they word. I'm still puzzled that no one has responded. It seems like no know anything about billing at vodacom but they good a signing up contract.