Double-debiting

Beginning of this month I was double billed. I have contacted the call centre more than 5 times, told to send proof of bank debit to an unmanned ‘proof of payment’ email and customer service. All I get are automatic replies. Call centre staff keeps giving me useless ref numbers and I’m told the matter is being escalated. It’s almost a month now. Yesterday I got a one sentence email saying I was billed for two separate accounts. I only have one account with cell c. This is very frustrating. If they have a billing glitch what are they doing to fix it? When do I get my money back? Will I get double billed again end of aug? Account statement still says I owe money!