Hi Gareth,
"Causation" is medical too - as am I !
No written report to post I'm afraid. I received a written quotation but not a 'report'. Didn't ask for a report but will be doing so from them and a second opinion as helpfully advised above. Following calling Audi (UK - not the dealership) I was advised to take my grievance to the Ombudsman. I did. That is where I still am three months on.
KR
Omar