Vodacom gives people access to your bank account

Vodacom has allowed some random peson / company take R1400 from my bank account. AND simply refuses to refund it. They did not even give me the name of the actual company that took the money, just Opera or something that acts as the middle man that lets other people just take money from your bank account. So essentially if you are a Vodacom customer you can go register on opera and take any vodacom customers money. You don`t need to provide actual proof of anything, simple claim whatever you want and Vodacom will take their customers money from their bank account and give it to the random 3rd party companies, of which Vodacom either don`t know the name or have in 2 months of struggling to get my money back not bothered to provide it. So if you are a Vodacom contract customer, I would recommend you close your account that they have access to, as they also ignored various requests to stop deducting money, refused refunds or proof of the 'service' for which they billed my R1400. Simply saying that they are keeping the money and that`s the final answer. I phoned my bank and had to block vodacom and reverse the funds. Then they phoned me 9 time in 1 day...to get the money, not help.