If they aren't in ducting, I would definately get Virgin to repull them correctly before anything goes wrong
Official price for this if you request it is £75. If the install is fairly recent then you will stand a good chance of having this waived.
If you were installed over about 3 years or so, you would probably have to pay for it. Though you could then dispute it in writing
Though, as with anything like this, it will be looked on a case by case basis.
Alternatively, let the contractors cut the cable, kick up a fuss with them, and have them pay for the repull
