Double debit order

Discovery Flexicare made a dubbel debit order on my account a week ago. It stil was nit returned after I have contacted them a few times and did press them on ther urgency to return the money that I need to do groceries with. The lady I had a conversation with numerous times over WhatsApp and phone calls, promised that the money would reflect in my account. I have tried to do a reversal from my side but the bank notified me that they're unable to do the reversal for me. This was not the first time that mistakes has been done. I am at the point to cancel and would not recommend anyone to use their services as the accounts is extremely *********** to process the debit orders correctly. They take the extra money probably monthly from customers to increase they're interest received from the bank. Why would they allow *********** people to keep on working there?