Can I connect my new hub to the existing phone line only?

You can't connect a VM hub to a telephone wall socket for broadband. The TEL1 socket on the back of the VM hub is to plug in a telephone if you use VM's landline as part of your package. You need a coaxial cable to connect to the hub.

Have you checked to make sure there is no other kind of connection? Sometimes there is no wall box, just a trailing cable. The cable could be hidden within, or behind, furniture. Occasionally only a very short stub of wire is left behind often hidden within a blanked-off fitting. A few examples of the kind of things to look for are in the images below from past topics.

https://community.virginmedia.com/t5/QuickStart-set-up-and/Untidy-installation/m-p/5433266#M239199

https://community.virginmedia.com/t5/QuickStart-set-up-and/Reconfigure-my-setup/m-p/5434572#M239308

https://community.virginmedia.com/t5/QuickStart-set-up-and/Diamond-cable-wall-socket/m-p/5430136#M238904

https://community.virginmedia.com/t5/QuickStart-set-up-and/First-installation-and-flashing-green-light/m-p/5434785#M239339

https://community.virginmedia.com/t5/QuickStart-set-up-and/No-wall-socket/td-p/5395897

https://community.virginmedia.com/t5/QuickStart-set-up-and/No-virgin-media-wall-socket/m-p/5395697#M235740

A wall box may be branded with the logos of an old cable TV company (not VM). Past occupiers of your property may have removed the cable and sometimes they are removed by other installers, such as satellite TV techs.

If you have a cable/plug trailing from the wall, you may need a coupler adapter to join two plugs together

https://www.diy.com/departments/slx-coaxial-connector-19mm/5028422001905_BQ.prd

Also available from the likes of Screwfix, Homebase, Toolstation etc.

If you have a plastic omnibox outside on the wall (where the VM cable comes in from the street) see if you can trace any wires from that into your home.

If no luck, call the pre-installation and delivery team on 0800 052 1734 explain the problem and request a tech visit to install a socket.

Hi Sy22 thanks for your post here in the Community although we're sorry to hear of the concerns you've raised here.

We can see that since you've posted in here, you've been able to get the issues resolved via other contact methods which is great news.

If you do need any further help or assistance then please don't hesitate to let us know!
Many thanks