Called my personal line. Gave them as many "No" or "not saying" answers as I reasonably could. Of course, there is little I can do about it as they are outside Europe. The missing country code on the caller ID was typical of these calls. Called at 18:44 UTC. They're going on the redlist!
They hung up just as I answered. I called the number back and got a buildiing or room monitoring audio with the time, temperature, no water, no intursion, etc.
Several calls everyday always hang up when I answer. I rang BT who said as it is an international number it cannot be traced and cannot be stopped but suggested I change MY phone number!!! Surely someone, some computer genuis can trace it? I rang back and got number not recognised.