Fnb to retrieve the money I sent by mistake to nedbank

I have a problem. On the 11th of February 2026 I mistakenly sent money to a wrong account number. I was trying to send to my brother and I sent to someone else. But I know the person the acc no belongs to. I tried calling fnb and they saying they cant assist me to reverse my m0ney cause it was an immediate payment. I went to nedbank at nedbank theu said I must be helped by my bank to retrieve the money. I am frustrated I need to use the money this weekend for a funeral. Kindly assist me to retrieve back thr money. The money is 15 000. The account holder says his account was handed over to lawyers so at nedbank they cant help him. Please assist I am running mad