BT voicemail Samsung s6

[Braker]

I never thought this would be a problem but hey ho. I have a refurbished and unlocked samsung s6 with a BT sim card. I've activated voicemail and I can ring voicemail. However if anyone rings me and the call is not answered the call will just ring out and wont divert to voicemail. I've contacted BT twice and the first call I was cut off, which I find not unusual ringing BT, the second call couldn't solve it. I've searched high and low on the internet involving many hours all to no avail. So, please can anyone help me.

[pottyperson]

Have you checked the phone settings? Open the phone app and tap menu (3 dots top right) > Settings > Calls > Call forwarding. "When unanswered" needs to be turned on.

[Braker]

Thanks for your reply, but I have fiddled around with that,  there was 4 options none of them work, I have 3 switched on the only one off is always forward.

[Braker]

I've just tried ringing my phone with always forward switched on and my phone does not even ring the call is cut off straight away.

[Andy005]

Hi @Braker,

I've just toggled Call Forward when unanswered on my S6 to on and it's now going to voicemail. Always Forward, Forward When Busy and Forward When Unreachable are all disabled.

What number does it say the calls are forwarded to? 

[Braker]

I've just tried your suggestion but it doesn't work on my phone. The voicemail number is 447953223571. Something seems to be blocking redirection, although I can dial the voicemail it just says you have no voicemail.

[Silentbob]

Ring 15712 turns on answer phone
15713 turns it off it may be worth a go it could be the other way around.
Also turn on all the forwarding settings except alway forward.