Struggling to get debited funds back

I am writing this on behalf of my mother Mrs M.A Ravele. She's so frustrated with FNB as she had a loan with them which settled on the 7th odf December 2020. She was told to pay R3876,60 which she paid but FNB debited money from her account on the 11th of December 2020 where R2211,62 was taken. She is frustrated as she need her money back, she received an sms stating funds were going to be processed back in her account within 24 hours after visiting FNB at Elim, till today there's no funds transferred in her account. There's a pandemic for crying out loud. How many trips does she need to make to FNB to get her money back.