If you are not so precious about retaining your number then AA is a good option. You can pick a local number for the £1.20 a month.
I was with VM several years back, and got loads of spam calls. It got so bad that I unplugged the phone and just left the answering service active. I still got a lot of junk messages, so I went to AA and took out a VOIP number, put that on an ATA and have never looked back. No spam calls.
We changed to EE a few years ago, fed up of VM and their lies and bad service. They gave us a new landline, but was soon full of junk calls again. I unplugged the line as we were not using it anyway, all our family had the AA number by now.
These days we are FTTP with EE, and they took the landline out of the package anyway. We don't have it any more. Like email with an ISP, think about changing to either your own domain or a provider that moved with you. If you're tied to your provider it gets harder to move in future.
EE Fibre 100 no phone