Had 2 calls asking me to press 1/2 after telling me that they will cut me off. What is in it for them?
If you respond, then they know there is a real person on the end, and will add you to a "suckers" list, and you will get even more calls, so just hang up and do not speak, or press any buttons.
They will also try to extract personal information from you.
Nothing to do with BT.