Home phone not working (busy tone)

[#1]

My home phone stopped working. Each time I dial a (any) number I get busy tone. Broadband over the same line works just fine.
Followed the faults procedure with a friendly CSC team analyst who raised fault ticket 35026631.
What is really surprising is that
a) broadband just works
b) 'fault' just occurred out of the blue
c) no clear reason has been given by the analyst, just that it may be a 'provisioning issue' or a 'fault'
So, if it is a 'provisioning issue' who is to blame for the inconvenience caused that leaves us without a landline on a weekend? The pattern here, if I may I guess, will be "Sorry, it was BT's fault, we've done our best".
There is of course the usual wording "Is the end user aware of potential charges? Yes!".
I'd add: "Is the provider liable for any charges about the mess caused? Yes!"
Not impressed.

[#2]

Phone line back to normal now.  I've added this info to the relevant ticket, but there's no way to close it.
No explanation whatsoever from PlusNet yet, but, of course, it's Sunday.
I would still like to hear an official investigation and an explanation of what went wrong.
Thanks.

[#3]

I'm glad to hear that your service is back up and working but unfortunately there's no retrospective testing or investigation that can be performed. As the fault was reported and later closed on Sunday, we didn't get round to reporting this to BT so they didn't perform any tests that we could reference.