They probably heard from CAR and decided to refund you. Their system didn't catch the fact that they had already given you vouchers.

I believe that it would be unethical for you to take both. In your complaint to CAR, you probably didn't mention that they gave you vouchers, so it was misleading. If you want to take the cash (which you are entitled to under EU law), then return the vouchers.

I believe that direct deposit is normal in the EU. Their payments systems aren't stuck in the 1990s like ours.