It was an incomplete service again. The sensor light stays on reporting the front hood is not latched although I tried hard slamming it down.
Two services ago, there was a massive fuel leak from the bottom of the car while filling up at gas station and I had the car towed back to Audi. It turned out some seal was not properly tightened. It was a life threatening mistake at that time and I did report back to Audi but didn't file further complaints.
It seems I would have to bring the car back in again for that sensor light issue this time. The service crew needs to improve on post service checkings for any unanticipated issue instead of having the customer find out on his/her own after picking up the car.