Double debit refund delay

Despite having a payment arrangement, Nedbank debited double my home loan and refused to refund the full amount. A refund of only half the amount was issued on the 19th and till today I have not received the refund.

The inconvenience of waiting and not being able to pay for anything has put me through hell. I'm definitely closing my account with them today. Their agents are so rude, literally transfer me from pillar to post or hand up while I'm still talking. I want my money as in yesterday