That's awful. Ours trashed the kitchen and left thousands in damages too. Some things we can fix through hard graft at minimal expense. The kitchen isn't one of them.
We had Polish builders in there once who sublet the rooms to different families, so it was a similar situation. They trashed it too, but not as badly as this lot. It wouldn't have been insured with that many people in the house and it wasn't legal for multiple families.
I've had the most productive week of my life trying to knock it into shape, mostly single-handedly, because my husband is on light duties due to having had an operation.
Will post an update soon.