Accidental payment

Someone accidently transferred money to my savings account and fnb is not able to reverse it, they want me to transfer the funds to my cheque acc which is not going to work because it will be deducted and I'll have to ask this person to wait until I can deposit money in my acc which is going to be in 2 weeks time and the person needs the money urgently. This past year has been the worst with this bank having such bad service.