as the original poster of this issue, I thought I should say that I have no regrets. However, I am fairly rivetted by your system : 3 lines and one used only for broadband. When we were on dial-up I toyed with the idea of 2 lines but now with FTTC the line seems to be coping with everything I ask of it.
[On the side issue and just to amuse everyone until about 3 years ago I had six landlines at home - home line, work line, fax line, slow dial up internet line, burglar alarm line and then my teenage son wanted broadband before anyone else did so his treat was his own line into his room for that.
Until a year ago I was still occasionally getting faxes but I dropped that line and the alarm line and moved one broadband line on to my work telephone number (I work from home); that dropped me down to 3 lines. I want to keep the home telephone landline so that would be two lines but despite efforts from 3 very techy teenage boys over 10 years we have not found a way with boosters and all sorts to get good wifi 3 stories up which is why we keep that separate line for the broadband on story 3 (it is a big house). I also find it quite comforting as we don't eat if wifi is down as I cannot earn, that there is a second broadband line anyway.
So that leaves us with work phone number (which has bb on it and this is all i will keep if I ever get rid of the boys) one one of my accounts and ; home phone number and second broadband package under the second account number. I could try to move the fast second broadband line/ account on to the hard to hear dodgy home number landline but I don't think I dare in case it all goes wrong for now so I will stick with the 3 landlines for now and then get rid 2 in about 6 years when the boys leave.]
I still however want to remove call protect but keep call minder and not solved that. It was a very complex thing to get the 6 lines down to 3 and move broadband on to my work line so I am not that keen to have to do something like that just to get call protect off and nor do I want to remove call minder on the home line as that is the line everyone rings if they have emergencies. I seem to be the very large family's main stay and support if they have any trouble ever anywhere. That landline was the numbercalled at 3am when we had a baby in difficulties for example so I want every number to get through to it and it to take messages always which is basically call minder plus no call protect.
The mods fixed it for me. I don't know if there is a generic solution. I'm happy without it.