If you use a phone which forces unknown or withheld callers to announce themselves, then you will stop all scam calls.
The BT4600 is one such phone.
Trying to simply block them, is a waste of time.
You can still use your old phone, if you still have it. Just plug it into the phone socket on the smart hub 2.
Caller display can be enabled via MyBT.
https://www.bt.com/help/landline/digital-voice--how-do-i-use-my-calling-features-
Thanks Keith, I have ordered caller display via My Bt and just discovered that I still have my old phone!
I daresay it can take a while for my caller display to be activated. Just rang my land-line from my
mobile and it doesn't display yet.
If you have done it via the separate options for Digital Voice, I would have expected it to happen quite quickly, as it does not involve sending an overnight update to the old PSTN exchange, which took 24 hours.