Reversal dispute

On the 30/11/2021 I was doing once off transfer from my Old Mutual Money account to an FNB account the beneficiary sent me a confirmation that my old mutual credit card declined but money went out . so when i consult with my bank (old mutual they want me to consult with FNB but i am banking with them. i have sent them prove from the beneficiary that they did not receive. Old Service its very bad refer to reference number that they gave me with no resolution MASC903962