Several calls from my "answering service"

[#1]

Hello, my first time on this sort of service. I've just had 3 calls purporting to be from my answering service - but I don't have one. I'm told to press 1 to pick up message. I listened to something garbled and was told to press 1 again to replay. I'v done this once but have had 2 further calls which I've just hung up.  Is this some sort of scam?

[#2]

Did you dial 1571? That's for the Plusnet free call answering service.

[#3]

Probably some one sent a text message to your land line. It calls you up then reads the message back to you in a computer voice.

[#4]

Ah Ha makes sense. Thank you.