Incompetence and deliberate lying

Nedbank double debited my home loan and I've been trying to get a refund since the 26th of March, the manager Meshach sounds almost annoyed that I keep calling to ask why I haven't received my money yet but he keeps on deliberately lying and making empty promises. I spoke to Siyanda who also **** to me. I should've received my money 2 weeks ago but because no one really cares about the customer they didn't place any urgency on it, in fact the first person I spoke to didn't even request my refund as they said they would. I have recorded phone calls of every interaction. I had to borrow money and seek favours from friends because of this which has been very embarrassing for me.