Thanks jimworcs!
So, quick update... I was pleased to get an email from Etihad Guest the same day I made my original post. They promised that they would follow up on my case straight away.
Confusingly, however, the also asked the following "
Since you have not received the card processed in 2010, please provide your complete postal address or an alternative postal address in order for us to facilitate a card replacement request."
Now, I do have my Etihad Guest card, it was sent out to me when I joined a few years ago. My postal address is also still linked to my account (I checked this online). So I'm not sure why I've been asked this question.
I responded, saying I already have the card. That was two days ago, so looks like the waiting has started again...