Standard Bank Executors - terrible service

My father passed away 3 years ago and Standard Bank were appointed the Executors of the Estate. For 3 years we have struggled to get answers out of Standard Bank on the progress. The Executors are impossible to get hold of telephonically and they only reply to every 20 odd emails that we send. When they do reply to an email they give us false information or repeat excuses they made last time. This has put my 77 year old mother through such stress and the delays have actually forced her to sell her house. I have personally attempted to contact the Executors with over 50 phone calls and over 200 emails over the last 3 years but I still have no idea what the hold up is and when the estate will be finalized.