I got the support on the phone and have a technician booked for tomorrow. The connection got back this morning but downstream power levels are still very low and broadband keeps intermittently dropping. I'll update this thread once I have more details.
It's working like a charm now. There was a section of the cable between the house and the Virgin media cables that was for satellite and it introduced a lot of noise and power loss. The engineer replaced and now every thing is working fine.