Update.
They have had the head apart and the valves have touched (all) they are doing a leak test overnight to see how many are bent. If it's all 8 (I'm assuming 8 of the 16 is the max number that could collide at one time) then the cost to rework the head and replace the valves, belts and pump etc is £1500 plus VAT.
Interesting though and food for thought, they reckon the cam belt is the original, in their professional opinion which puts me in a situation as it was sold to me as "belts done", it even states it in the service book.
First thing to do is get it in writing. Second thing is contact the place you bought it and threaten legal action unless they pay for the damage.