Same here, booked a flight MNL-AUH-FRA return in Z and only offered "credit" after all flights were cancelled.
According to Filipino law (where I booked) and Etihad's own conditions of carriage, para 10.2, I am entitled to a full refund.
Unfortunately, this doesn't fall under the European regulation, and I doubt there is an Etihad entity in the Philippines I can sue.
So, I'll try a charge back through Amex which I used to pay the flight. Holding my breath...