Issues reconnecting after moving home

We've recently moved but unfortunately the cable service hasn't been connected.

The contractor arrived at the property before we moved to install the cabling. We were assured this wouldn't happen but unfortunately, the wall box in the wrong location (under the level of the floorboards of the room the cabling will be fed into). Additionally, the cabling was laid in the soil just below the surface of the grass (which may be hit by the lawnmower) and the wall box wasn't secured.

After a week or trying to speak to someone, I'm unsure what to do. I've communicated via the customer help lines (voice and web chat) and the engineer that has been out twice isn't the correct person to (re)connect the cabling. The engineer that has visited has tried to help but nothing has been actioned since. I've put in a complaint but this hasn't been answered yet.