If you wish to return a call directly from the “Voicemail” area of the Self Care, you need to upgrade your BNESIM account to BNE Pro. BNE Pro is free for the first 30 days.
Once you upgrade to BNE Pro, you will find all your voicemail messages – and the numbers that left them – in the “Voicemail” area of the Self Care. “Tap for more details” in the “Voicemail” area on the Self Care home and then tap the phone number you want to call back in the “Messages” area.