Impossible trying to change debit order details

It is near impossible trying to change debit order details with Vodacom. The call centre keeps cutting the call and Tobi chatbot cannot assist. It really is unpleasant dealing with Vodacom. My wife has a new bank account and closed her previous account, so Vodacom cannot hold us liable if they dont debit the new account. We tried everything, but client care is non-existant with Vodacom