Yes. Bobobuk, could you proveide a postcode? That will likely tell you which cabinet she is connected to, etc.
Either way, it's sort of a moot point. If she thought she was on ADSL, she is mistaken, and has a very acceptable VDSL connection (i.e. FTTC).
Course of action: If she's paying ADSL prices, and nothing more. DO NOTHING, and of course pretend never to have noticed if they question you.
If you're getting charged more than ADSL prices, phone and complain immediately because they have made an error, which has caused your whole family great distress over the Christmas period. I mean you're surely thinking about inviting the local news people round, aren't you, because she feared that she couldn't afford any presents for her grandchildren? Put a Christmas tree up with no presents underneath it, so the local camera crew can shove their cameras right under there.
Edited by gazzyk1ns (Wed 21-Dec-16 21:47:17)