Poor customer service

I have a loan with Nedbank that I couldn't pay due to unforeseen circumstances, and my account was handed over to NRB. I made a new arrangement with NRB, and they started debiting my account. However, Nedbank still processed two debit orders, and now neither party is willing to assist me in getting a refund. Can I please get my refund as soon as possible? I'm extremely frustrated with the lack of cooperation from both Nedbank and NRB.