Just to let you know: I decided to send in my missing avios query today. On Iberia's website once you log in it says claim missing avios, and something about "tell us and we'll fix it for you". Gave me a bad feeling straight away. Needless to say the email address they tell you to write to to claim missing europcar avios is:

"Delivery to the following recipient failed permanently:".

The email address doesn't exist anymore.

So I went to the Europcar site and filled in the form there instead. No confirmation anywhere after submitting it.

Pretty hopeless.