Over the years there have been a number of OpenReach / British Telecom scam phone calls from various bogus departments.
There is a new version doing the rounds.
Answer the phone and you receive a recorded message telling you that suspicious activity has been detected on your internet connection. Unless you respond immediately by pressing 1 your connection will be suspended in 30 minutes.
Absolute rubbish obviously. OpenReach do not monitor your activity. And if they did decide to monitor they would never be able to admit they did.
Over the last week I have received one of these nearly every day. My connection is still live, and the suspicious activity will continue.