Well, I've (thankfully) not had anymore 'empty' phone calls
I declare TPS & Silent Call Gard a sucess
(they do say it can take up to 30 days for it to kick in, but usually, it's a lot quicker than that...)
Both are free and well worth the few seconds bother to sign up to. As for silent call gard, it just needs to be rethingied every 12 months, but that's not even a hassle!
TPS you do it once.
It's really been well worth the effort