Bad service received from Bidvest Bank

Visited Bidvest Bank in Wesgate to request bank statements on behalf of my late sister, I had a latter from Master of high court requesting them to give me the outstanding balance in order to facilitate the Latter of Authority but they simply refused saying they don't recognize the latter from Master of high Court. Managed to receive bank balance from other banks. The service was pathetic to say the least, supervisor was very arrogant.