I think this is a clever scam "It claims to have some 15m numbers in its database." I can claim I have that many numbers too. The reality of it is, they most prob don't. I think what there doing is spreading there new service all over the place, so when you ring them up or text them to "opt out". Then wham they now have your number to do as they wish. could sell on your number, use it for a partner or sister company. I wouldn't get intouch with them at all.
I think I'm with you on this.
We know there is a directory now but if you attempt to opt out are you just confirming your number to these guys? Will they then say that your number was still on the list they got hold of before you opted out?
I know trying to opt out for your BT phone is nigh on impossible.