Disgusting service provider ever

Missed a payment with nedbank and made and arrangement to debit my account with the current instalment and a third of what I owe for the missed installments. Guess what nedbank debit my account twice for thrice and when I called I was promised a refund of 3323 and given a reference #. 5 days after still don't have my money back. Called the whole day and I am being sent from pillar to post. Disgusting service.