Deposit money issues

Hi can you Please help on a refund from both of these companies. Sani car rentals claim that they had not received a deposit amount from my bank but to my acknowledge the money was processed and when I called nedbank that the money was transferred back into my account but when I ask for a proof of the transaction, nedbank tells me that they can not give it to me. On the credit bank statement the transaction does not even show proof of the transaction so I am going around asking these two companies what is happening and no one is able to give me answers as to what exactly happened with my money. Please help me sort this issue out ~lebohang