POOR service from Standard Bank

We are administrating deceased estates and need a certificate of balance from Standard Bank for the deceased's accounts he had with Standard Bank. We have send the relevant correspondendce to them in August 2018 and now 3 (THREE) months later we still did NOT receive anything. The administration of the estate can't move forward as we can't do anything without the documents from Standard Bank. We phone them more than once daily with no luck. It is realy frustrating working with Standard Bank.