Without wanting to sound picky , its really the idiots that cut your cable you should be trying to get hold of- They cut it, they are responsible for the costs of re-instating it.
Whilst VM will do their level best to get you up and running again, If the workies have hit VM ducting and now intend to infill, could be a MAJOR problem, they need to stop until there's a proper assessment done of the damage caused and how to put it right.
Usually there's a board/sign/some equipment with the contractors details on (especially if there's an open hole) , see if you can get hold of them and explain the situation. Personally Id be pretty miffed if they continued to infill after Ive reported they have hit my utilities....