What would Alexander Graham Bell say?

This is a nightmare!
It's my old friend Talk Talk, a company I have found very underhand, but fortunately this story isn't about me, it's my Mother In Law's problem.

It's still not resolved, but here are the facts:

My M-I-Law and husband have a full package with Sky. TV, Broadband & Phone. No problem.
Being the 'techy' son in law they ring me with any issues, last week it was the broadband. It had stopped working and an orange light was permanently on the modem. I suggested resetting it and left it at that.

So, it turns out that didn't work, so they rang Sky for assistance.
Only Sky told them they couldn't help because they were no longer with them.

???
Huh?
What did they mean?

It turns out there are unscrupulous ISP providers (you know the ones, who knock at your door all hours to see if you'd like cheap broadband and free calls) who are now no longer bothering to knock, they just fill in your details and send them off.
What is surprising (as I have had this attempted on me...yes, by TalkTalk) is that Sky didn't contact the MILaw, they just switched them.
Because of the switch they also, unbeknownst to them, have a new telephone number, their old one has already been recirculated by BT.

So, they find their new number, Sky though won't tell them who their new ISP is, they seem uncertain. They mention TalkTalk, but do say it may be another company.

???

If you think this is a mess, just wait.

So, they no longer have broadband, they have lost their number (which means the hospital cannot ring them over important issues coming up), but BT have said their new number actually belongs to a completely different person.

???

It belongs to the couple who moved in across the road last week!
So, they go and visit the new couple, and sure enough the number they now have BT have said belong to the new couple, BT were supposed to come and connect them last week but failed to do so. Why, because BT think the line is up and running, which it is, just at the wrong house. So the MILaw's number is temporary at best.
They have also been told that if the number is given to the proper person then they could be without a phone for "quite some time".

Maybe I should mention, they don't live in a town or city, they live in a very rural part of Brecon. There are no Internet Cafe's around, and no pay phone's to nip too. These are pensioners who do their best to understand Google.

It's not yet resolved. Sky have said they are looking at this at the highest level.
Ofcom have said if TalkTalk have been found to have been underhand their will be a huge fine.
I suggested going to the Citizens Advice Bureau as well and to start to use the magic word "compensation" in all their dealings.

What a mess.