Unable to get access funds in closed business bank account

I closed my business account and a customer accidently paid into the account. The funds was not reversed back to the customer.

I went in to the branch and they can see the funds however they can not assist me because the account is closed.

I want Nedbank to sort this out immediately as they are *****ing the money. If I dont receive feedback I will report to the ombudsman.

This is unacceptable