I'd like to get a few things ruled out as several things can be at play here. I want to focus on the features that may be on the landline first so I can take a look. Once we finish looking at the features on the line, we can look at the equipment such as the handset and cabinet for example.
On the Virgin Media line, do you know what features your mum may have? Typical examples are Free Voicemail, Caller Display, 1471. Some customers have them removed so I just want to make sure before I go in to the switch and tinker.
Thanks. I've just spoken to your mum to get clarification and have checked the switch again but cannot find any issues. I've raised a ticket on her account for our Second Line Faults to take a look. They may call her on her mobile or landline so please ask her to listen out for a call. Please allow 48hrs for them to pick it up and let us know how it goes.
Ah, so the mobile number was yours that is on her account. Can you explain to your dear mum in case she's wondering what's going on. Please send me a Private Message what her own mobile number is as they will want to speak to her on it to free up the landline to test.