indeed, i hadnt thought about it like that to be honest, i think a phone call and an email with the pictures in will be sent.
real shame as i like the garage and the people who work there
....You need to calmly but strongly read them the riot act. It might be the fault of just one sloppy employee and so the garage will thank you for letting them know. Such sloppiness is actually potentially very dangerous and I would make a particular point of telling them that.
I would put it all in writing (email should do) so it's on record and address it to the head of the company (marked Confidential if snailmail). Find out his direct email.
What to do next should depend on how the garage responds but it would be a waste of time and also sour your relationship if you go straight to VW UK without giving them the opportunity to respond and give you assurances for the future. If they don't respond satisfactorily, then go to VW UK and your case will be stronger with copies of correspondence.
Let us know what happens please