Liberty Life uncontactable

We are having difficulties in contacting Liberty Life. My dad would like to change the bank account in which Liberty Life deposits his annuity. We were unable to receive any feedback from the Johannesburg and the Gqeberha office. We have a very big problem. My dad needs that money in order to provide for this family. Nobody picks up the phone at Liberty and their has been no response to the email. This has been challenging and upsetting for my dad.