Unfair double debit of my account

Good evening,how are you?I have a home loan with Nedbank since 2017 and it’s my 2nd bond with them.During Covid19 I wasn’t working for 2 years so I made arrangements to pay half of my bond monthly installment.September last year I went back to work and started to pay my full installments even though I had to take a salary cut.I’m in arrears for one month and I made an arrangement to pay an extra R500 every month.My problem now is that Nedbank home loans deducted 2 times my monthly installments on the 27th May 2022.I called their customer center and told them to reverse back the other money into my savings account and I was told that was not possible.The lady I was talking with said they can only do the reverse on Monday the 30th.I told them that was unacceptable as I had other debit orders from my insurance policies that needed to go through on the 27th May 2022.I asked to speak to a supervisor and I was told she was in a meeting and that they will call me back.Nobody bothered to call me back and now my savings account is on minus cause of the bank charges incurred due to lack of funds when my other insurance debit orders couldn’t go through.I have been a client of Nedbank for over 2 decades and I really wish they can treat their clients with care.Unhappy and disappointed indeed.