Blocked account because of an affidavit from third party

We opened an NPO account with Nedbank and one of the members of the NPO is a Nedbank employee and a manager in the branch where the account is at. The account has been blocked and placed on hold with a teller alert twice without my knowledge all because I had a fallout with the members one of them being a branch manager at Nedbank. I was told by the banker that Nedbank was instructed by the police to block or put a hold on the account and asked for the name of the detective that's incharge of the case and the banker refused to give it to me. I then went to the police station were they said the case was opened and I found out that there wasn't a case opened and they never instructed Nedbank to block the account. I took the matter to the Nedbank Regional Office and when I got there the only document that was from the police station was an affidavit from one of the NPO members. So the account was blocked because of an affidavit from third party without a valid court order. I have to report back to the funder of what the NPO has done with the funds that they gave to the NPO for it to help change the community's lives, mainly the kids. But me being the one that signs on the account can't access the funds all because of an affidavit and staff members that decided that because we had a fallout and they revoked their signing powers on the account and said they don't want anything to do with the funds and the NPO. I am very disappointed of how staff can misuse Nedbank's facilities in order to be spiteful not caring who gets hurt in all of this (community).The account is still blocked since 5th July 2018 for no valid reason.