Thought 1571 service was included free in my package

[#1]

I press 1571 button and BT say I haven't got that service.
Looking at my Account and settings I have a green traffic light on that extra.
BT ask me to press 1 after saying there might be a charge.
Advise please.

[#2]

Go to https://portal.plus.net/plustalk/index.php?page=wlr_add_call_features and click on Voice Mail at £0 per month to activate it
If it is already activated you will need to raise a ticket asking why it isn't working

[#3]

Thanks Jim yes green selected button still showing, question asked of support team.