Weary traveller,
I've shown your tale of woe to the GM of Europcar here in Australia, and if you contact their Customer Relations Manager (Matthew Burns) on
[email protected] and request a review of your problem he will look after you.
Whenever you hire a car make sure that the inspection form is accurate before you sign it: that applies whoever you hire from and if there is a ding that you don't have listed it can come back to bite you.
I've had excellent service from Europcar such that they get all of my business these days, but I would point out that all hire car companies can slip up now and again. I'm a President's Club member with Avis, but that hasn't prevented odd errors happening: I find a polite but firm contact with the company reaps far more reward than having a moan on an internet forum!
Mind you, it may have been to your benefit in this case