Sorry to hear about your knee, I was in a compression cast for 2.5 years, for Charcots foot )bone softening) been out of that for over a year now, so I know how you feel. Possibly the best thing you can do is get a coupe of inspections from independant paintshops as well as the dealerships approved repairer, then take it forwrd from there. The dealership should then take some notice. Good luck.