After having 3 scam phone calls in quick succession last week BT chat added the 1571 service to our account. Whilst I can add numbers to the blocked list through the app when I dial 1571 I get the message that it isn't enabled on this line. According to the app we have 1 message that we cannot access. Also, if we do ever gain access to the message is it free to listen to the message please? Thank you.