Payment twice

I made and EFT and the money was deducted twice, there is no option to pay it twice but my money was deducted twice. I immediately called the bank and asked them to reverse this bec I don't know why it was deducted twice, its been more than 3 weeks now and I still did not receive my money back. When I try to follow up all they indicate is that its under investigation, I don't understand what to investigate as its a mistake on their side, on top of that you have to pay them R160 for their mistake. I'm completely done with this, bad service. It is my money but you have to fight with them. I will not recommend this bank to anyone.