Thanks for the prompt!
I got my car back on Tuesday evening. New engine block and cam in, and strangely a new clutch plate. Head and other bits from my old engine.
Garage didn't accept that they had caused it, but didn't charge me anything to put it right. So no complaints on that. I'd lined up an independent inspection in case, but not needed.
If anyone here wrote off a blue 1.4tsi 3 door 2015 with around 65,000 miles on it, thanks, I've got most of your engine.
I had it running on the drive today, and listened hard to the engine. Slight ticking sound, not quite sure was there before. Garage suggested an oil change was needed once it had settled in.
I'm now pondering if to trade in and move on. Working from home at the moment so no need to make a hasty decision, but not sure I'll trust it for a while.