Internet and phone not working?

[Southpaw]

Well you are obviously in the UK so you are using a BT land line rented out to other licenced carriers.
Your telephone line has an intermittent disconnection fault at the very minimum, and if it is after your main socket in your premises then it is your responsibility to fix or get someone else to fix, but this is unlikely in my opinion.
If it is the line from the exchange up to and including the master socket that is at fault then it is the responsibility of your service provider to repair for free, and in my opinion that is likely to be the case in this instance given your lengthy description.
You can get some advice about proving the fault in or out of your property from the BT fault reporting site sub menus;
https://www.bt.com/consumerFaultTracking...URL_faults
Broadband can work rather poorly on a bad line even if one of the two wires used is duff, a telephone cannot, it needs both.
Christmas is a rather unfortunate time to have such a fault as the companies will not pay their staff the extra money unless it is an absolute emergency.
Apart from checking that your own equipment is OK, which is a bit difficult without a working telephone line it has got to be said, then it is a matter of waiting for Virgin to ask Openreach to fix your telephone line fault after which your broadband should magically start working again.
Sorry I can not be more help, ex BT Bob.