Ghost deceased department

My younger brother passed away, he was having a personal loan with nedbank of 118k, we settled the account in January, send nedbank the proof of payment, I have have since then requested for a paid-up letter confirmation until today I am taking pillar to post with no proper response. I have visited 5 different nedbank branches with a hope to get a soon but still nothing. I have made thousands calls which half of them were escalate but until today nothing is been done. I regret settling that personal loan, i should have used that amount of money to support my mother with since she's a pensioner. Worse about about it, on the same account nedbank owes us a refund of 2k. I have provide letter of authority and I am told to open a state account over amount 2k, my young brother has no state listed under his name, he was only owing nedbank. Nedbank deceased department is unreachable, every email send to them no one respond it besides the auto response you get.