What I would do is ask them to install it loosely over the bricks and driveway etc.
So the cable is just on top of the bricks... Get them to leave a lot of excess wire.
They can leave it with a green kind of cover going around the wire ready to be buried.
Then in my own time I would lift up the bricks and hide the cable etc.
Or I would lift the bricks etc in advance of the install so there's a clear route for the cable to go.
It's unlikely they will lift the patio up themselves, in fact they will not as if it goes wrong virginmedia will have to pay to fix it.
Generally virginmedia will do whatever makes the customer happy but do not lift carpets, patios, floorboards etc.