I'm really sorry to hear of your Mother's situation. Who is the account holder of the broadband service at the address? Is it your Mother, the landlord or someone else?
Chris
The move to Digital Voice categorically doesn't NEED any removal of the copper line. If it was simply a change to DV, nothing is physically required at the premises other than simply plugging the phone into a different socket.
A move to full fibre is a completely different activity and not a requirement for DV.