Car was dirty and damaged, with head-rests missing; customer service little responsive & not helpful

The ground staff was very friendly and helpful. I was upgraded to a bigger vehicle, as the one rented was not available. The car unfortunately was not in the condition I expected it to be in: - I was told it would be perfectly fine - It was scratched and bumped - It was dirty outside and inside (full of sand and dust) - We found it with the backseats were reclined - Two of the head-rests for the backseats were missing - It seems the car had not been checked and cleaned after the previous rental The Europcar customer service was unfortunately neither very responsive nor helpful.