VODACOM ...bad bad service

In July I noticed that may Vodacom debit order was returned. I phoned them and told them. Only then did they notice they had a system problem. We arranged that they take the debit order again on the 5the, and according to my bank statements it show the debit order went off again. Now in Nov they took a double premium from me for July THAT HAS ALREADY been PAID. I have sent multiple emails with the proof of my bank statement that Vodacom was paid NO RESPONSE Two of my other debit order were returned due to insufficient funds because a DOUBLE premium for Vodacom has gone through my account. Who's going to pay for the extra bank charges?? And when will I get my refund. I keep sending mails and all I get is we are busy working on it!!!!