Fnb

My husband passed away on the 18th April 2019. We both had 32 day accounts with fnb. I closed the accounrs and asked for the money to be paid to me. I recieved the amount that i thought was right and used it to pay for his funeral. Now it turns out that fnb by there own admission transferred the wrong amount to me and are trying to proceed with legal action against me. I am in such a state. I am unemployed and i have called fnb legal 3 times this morning trying to sort this out but the number just goes to voicemail. It was there mistake and becsuse if the circumstances i didnt realise. Now its my problem and i dont know what to do.